NEUROPSYCHOLOGICAL ASSESSMENT OF ADOLESCENT POLYDRUG

USERS AND NEUROLOGICALLY IMPAIRED ADOLESCENTS

by

MICHAEL J. RATHEAL, B.A., M.Ed.

A DISSERTATION

IN

EDUCATION

Submitted to the Graduate Faculty of Texas Tech University in

Part ial Ful f i l lment of the Requirements for

the Degree of

DOCTOR OF EDUCATION

Approved

Accepted

December, 1988

10^

to\' ACKNOWLEDGMENTS

I wish to thank Dr. Paul Dixon for his support in

preparation of this study. Not only in this effort, but in

my academic career he put in to practice the theories of

learning and motivation which provided a structure for the

enthusiasm I felt for this experience. I appreciate the

support and expertise of my committee: Dr. Gerard Bensberg,

Dr. John Nevius, Dr. Arlin Peterson, and Dr. Gerald Parr.

I also thank my fellow students for their support and

stimulation throughout this process.

I would like to acknowledge the support provided by

Dr. Ray Brown who was employer, colleague, and friend

throughout this project. He contributed emotional support,

encouragement, and direction in reaching this goal.

My most intense gratitude goes to my family. First of

all, to my remarkable husband, Otto Ratheal, who not only

tolerated the stress of this experience and took good care

of me and our family, but spent countless hours preparing

the final copy. My sons, Devin and Ian, provided ongoing

inspiration to complete this task so that I could build

with Legos and make cookies without guilt. I thank my

sister, Stephani Windham, for her undying sympathetic

encouragement and finally my mother, Nita Hisey, who made

me believe I could do it in the first place.

i i

CONTENTS

ACKNOWLEDGMENTS ii

TABLES vi

CHAPTER

I. INTRODUCTION 1

Statement of the Problem 1

Purpose of the Study 3

Limitations and Considerations

of the study 4

II. REVIEW OF RELATED LITERATURE 8

History of Drug Abuse

in the United States 8

Adolescent Drug Use 13

Assessment of Cognitive Functioning . . . . 17

Cognitive Functioning of Polydrug Users . . 23

Summary and Review of Hypotheses 35

III. METHODOLOGY 38

Subjects 38

Instruments 39

Demographic and Background Data . . . 39

Medical History 39

Demographic Data 40

Psychological Functioning 40

Measures of Cognitive Ability . . . . 42

General Intellectual Ability . . 44 111

Academic Achievement 44

Memory and New Learning 45

Visual-Spatial and Visual-Perceptual Ability 46

Higher Conceptual Processing . . 46

Attention and Concentration . . 47

Design and Analysis 48

Procedures 49

IV. RESULTS 52

Descriptive Data 52

Subjects 52

Demographics on Polydrug Subjects . . 53

Medical History of

the Polydrug Subjects 55

Categories of Drugs Used 55

Psychological Functioning of Polydrug Subjects 60

Medical History of the Neurologically

Impaired Subjects 61

Clinical Impairment Ratings 61

Hypothesis Testing 63

Hypothesis 1 63

Discussion of Cinical Significance

of Group Means 63

Hypothesis 2 74

V. DISCUSSION AND CONCLUSIONS 77

Summary 77 TV

Discussion of the Study 80

Summary of Results 87

Implications for Further Research . . 89

Implications for the Professional . . 90

Conclusions 92

REFERENCES 94

APPENDICES

A. MEDICAL HISTORY QUESTIONNAIRE 100

B. DEMOGRAPHIC QUESTIONNAIRE 102

C. GLOSSARY 105

TABLES

1. DEMOGRAPHIC CHARACTERISTICS OF ALL SUBJECTS

2. DEMOGRAPHIC VARIABLES OF THE POLYDRUG GROUP

3. MEDICAL HISTORY QUESTIONNAIRE

7.

8.

9.

4. CATEGORIES OF DRUGS USED

5. FREQUENCIES OF CLINICAL IMPAIRMENT RATINGS

6. FREQUENCIES OF UNIMPAIRED AND IMPAIRED CLINICAL RATINGS

COMPARISON OF NEUROPSYCHOLOGICAL TEST RESULTS OF POLYDRUG USERS AND NEUROLOGIC GROUPS

COMPARISON OF STATISTICAL FINDINGS AND CLINICAL IMPAIRMENT RATINGS ON INDIVIDUAL TESTS .

T-TEST COMPARISON OF CLINICAL IMPAIRMENT RATINGS

54

56

58

59

62

62

64

70

76

VI

CHAPTER I

INTRODUCTION

Statement of the Problem

Drug use is a problem which has become part of our

"cultural clothing" (Parsons & Farr, 1981). Millions of

people are involved in the use of illegal substances and

their use has become so widely accepted that drugs such as

marijuana and cocaine have been casually accepted as part

of social gatherings. The exploration of illegal drug use

and abuse is extremely complex and assessment in this area

only began in the early 1970*s. Parsons and Farr (1981)

relate the difficulty in studying this question to the

numerous factors which contribute to drug abuse and the

historical paucity of adequate measurement tools in this

area.

The acute effects of drug use and drug abuse are well

documented in medical literature. Whether or not long-term

cognitive dysfunction is associated with intense or chronic

drug use has only recently been investigated (Grant &

Mohns, 1975; Parsons & Farr, 1981). There is a well

established pattern of cognitive deficits associated with

chronic alcohol abuse but questions remain regarding the

contribution of nutritional deficits, possible premorbid

brain dysfunction, and toxic additives to the findings.

Well controlled studies of populations using a single

category of drugs; sedatives, marijuana, stimulants,

hallucinogens, and narcotics, found no lasting cerebral

dysfunction.

It appears, however, that abuse of a single category

of drug does not represent the current drug use pattern.

Rather, a pattern of simultaneous and sequential drug use

is typical of the adults and youth currently involved in

drug use; therefore, the question of the effect of polydrug

use on cognitive functioning needed investigation. Six

studies were located which attempted to respond to this

question (Adams et al., 1975; Bruhn & Maage, 1975; Grant,

Adams, Carl in, Rennick, Judd, & Schooff, 1978; Grant et

al., 1978b; Grant & Judd, 1976; Grant et al., 1976). With

the exception of one study located in Denmark (Bruhn &

Maage, 1975), the studies were immediate precursors to, or

part of, a grant funded by the National Institute on Drug

Abuse. These investigations documented long-lasting

cerebral deficits in polydrug abusers whose mean ages

ranged from 25 to 26 years. With the increasing drug use

by adolescents and the documented trend toward polydrug use

in this population (Pandina & White, 1981), the question of

the effects of chronic, multiple drug use on brain function

needs assessment for this group.

Purpose of the Study

The research which supports a connection between

polydrug use and cognitive deficits has been done on a

young, but not an adolescent, population. Further, the

studies were completed at a time when "designer drugs" were

not being used. This study provides empirical data

regarding cognitive functioning of polydrug abusing

adolescents relative to a sample of neurologically impaired

teenagers who were matched for age. There are several

reasons why this data may be valuable to professionals

working with treatment of adolescent drug abuse:

1. Adolescent drug use is viewed as a failure to meet

the challenges of adolescent development; identification of

cognitive impairment associated with drug abuse may con­

tribute to prevention arguments, to motivation for seeking

treatment, and to reduction of recidivism.

2. Identification of cognitive impairment in polydrug

abusing adolescents may assist treatment providers in mod­

ifying therapeutic approaches to accommodate an individual

patient's abilities.

3. Identification of cognitive impairment in a young

population of drug abuse may suggest the existence of pre­

morbid levels of cognitive deficit which could assist in

identification of a vulnerable target population for

special attention in prevention services.

This study provides additional data regarding

demographic and psychological functioning of adolescents

who are involved in polydrug abuse to a degree which has

identified them as in need of inpatient treatment.

Limitations and Considerations of the Study

This study was conducted in an inpatient hospital

treatment setting and certain limitations and restrictions

were necessary as a result of the need to avoid disruption

of the program. The patient's inpatient status was not

within the control of the examiner.

The most revealing information about the effects of

drug abuse on cognitive functioning would accurately

account for levels of drug use, both cumulative use and

intensity of single episodes of use. Obtaining a truly

accurate picture of drug use patterns from a self-report

measure has limitations. The subjects may have memory

difficulty for periods of intense drug use. A need to give

socially desirable responses may affect the patient's

reporting of drug involvement.

The procedures used in this study, neuropsychological

measures of brain functioning, are typically used to assess

identified brain pathology such as tumors, stroke, and head

injury. Their use in identifying less specific and

possibly reversible deficits is less well established and

therefore validity of the measures may be questioned.

The issue of deficits itself is somewhat ambiguous. A

child may show a pattern of strengths and weaknesses on a

psychometric measure of intelligence, and although some

abilities may fall in the borderline range of ability they

do not necessarily indicate deficient brain functioning.

The measures used must cover both broadly and in depth each

major category of ability in order to describe levels of

functioning and, even then, it is the pattern of perform­

ance, rather than any individual test which truly indicates

level of ability.

The confounding effect of psychopathology on brain

function must be dealt with in attempting to describe

causal factors for any observed brain dysfunction. The

relationship of illegal drug use to psychological malad­

justment has been the predominant focus of the literature

dealing with attribution of causes. Several studies

(Grant et al., 1978; Kilpatrick et al., 1976; Penk et al.,

1979) have found evidence of psychological maladjustment in

drug abusers. There is research support for dysfunctional

cognitive ability in chronic and acute schizophrenics

(Rodnight, 1983). Lezak (1983) states that "the incon­

sistent or erratic expression of cognitive defects suggests

a psychiatric disturbance" (p.233). Therefore it is

important to differentiate between deficient functioning

which is related to personality characteristics and de­

ficient functioning which is related to impaired brain

integrity from drug abuse.

The existence of possibly lower levels of premorbid

functioning must be differentiated from drug related im­

pairment. Parsons and Farr (1981) state that performance

on neuropsychological measures is highly correlated to the

subject's general level of cognitive ability. They further

discuss the possibility that some users of illegal drugs

may have lower levels of ability to begin with, resulting

in failure experiences, which could represent a contrib­

uting factor to involvement with drugs rather than a result

of drug abuse. This presents a problem because of the lack

of information about premorbid functioning on the patients

in the study. If this information were available, analysis

of individual patterns of functioning would yield compara­

tive data which would be more descriptive of possible drug

effects.

Both of the subject groups in this study include males

and females. Laterality and functional differences have

been consistently demonstrated between the sexes with

females performing better on verbal measures and males on

visuospatial measures. Lezak (1983) discusses the differ­

ences between males and females in deficits related to a

unilateral lesion, while men show significant impairment on

the side where the lesion is located, women show more dif­

fuse deficits. The same kind of differences are found in

studies exploring the lateralization effects of handedness.

The most stringently controlled study of brain impairment

would attempt to minimize the variability of cerebral

organization within each subject group by selecting perhaps

only right-handed males but this extent of exclusion was

not possible in the present study due to the small subject

population available.

CHAPTER II

REVIEW OF RELATED LITERATURE

With the onset of public awareness regarding substance

abuse a search for causes and effects began. The problem

of the abuse of psychopharmacological drugs has been laid

at the door of parents, peers, environmental stressors, and

improper medical supervision of addictive substances. No

pattern has been empirically defined for movement from the

use of "soft" drugs such as marijuana and alcohol to "hard"

drugs including barbiturates, amphetamines, and opiates.

Nevertheless, there is evidence that drug abuse is increas­

ingly best described in multiple use terms (Kornblith,

1981) and that cognitive deficits are associated with

polydrug abuse.

History of Drug Abuse in the United States

The entry of middle class, white youth into the drug

scene of the 1960's and 1970's presented a troubling phe­

nomenon to our society (Josephson & Carroll, 1974). As

long as drug use was confined to a lower class, minority

population it seemed somehow less odious and more under­

standable. Kissin (1982) states,

The history of drug dependence is the history of man's search for 'the occasional release

8

from the intolerable clutch of reality' through the taking into his body—by ingestion, inhalation, or injection—of some magical chemical substance, (p. 2)

It did not seem to be a societal failure when the lower

classes of an industrialized nation needed more "escape"

than other groups, but when the use of drugs became wide­

spread among advantaged youth the message seemed to change.

Josephson and Carroll (1974) suggest that this phenomenon

was interpreted by parents and parental surrogates such as

schools as a threat to "self-control and the work ethic and

therefore the very moral fabric of society" (p.xvi).

Kissin (1982) and Blum (1969) review the history of

drug use. Numerous artifacts suggest the existence of beer

from about 6400 B.C. (Blum, 1969). The discovery of dis­

tilled spirits made alcohol much more readily available.

Kissin (1982) indicates that the idea of the "drunkard"

appeared and there were epidemics of alcoholism among

England's lower classes until the government levied a tax

which put liquor beyond the economic reach of the poor.

Kissin (1982) indicates that the use of psychoactive

drugs was limited by geographic availability with the

earliest recorded use of marijuana in China in 2737 B.C.

For centuries the drug was known outside the Eastern cul­

tures but was not widely adopted. The use of cannabis in­

creased when the Napoleonic soldiers returned from Egypt

with hashish. Its early use in Europe was confined to the

10

artistic and literary elite. The early use of cannabis in

the United States followed much the same pattern.

Other botanical substances, cocaine and plant halluci­

nogens, were likewise confined to specific geographical

areas initially. Kissin (1982) and Blum (1969) discuss the

use of psychoactive substances in many religious ceremonies

and Kissin notes that the peyote ritual of the Mescalero

Apaches is a legal practice in the United States today.

Availability, however, is not the only variable predicting

the use of a particular drug. Kissin (1982) states that

cocaine use has been dated to pre-Columbian societies but

spread very little to the conquering Spaniards. The author

suggests that the method of ingestion, chewing the leaves,

may have been culturally unacceptable. After the active

ingredient was isolated, it was used by a German military

doctor in the 1880's to relieve fatigue among army troops.

The later findings related to the addictive properties and

induced psychosis essentially eliminated its use medically.

Stating that "health hazards are not the only factors

underlying public concern about drugs" (p.xxi) Josephson

and Carroll (1974) discuss that while evidence is strong

for the health hazards presented by certain drugs they

continue to be protected by our society. Some drugs have

become such an accepted part of American culture that they

are not considered drugs at all. Nicotine and caffeine are

11

the most commonly used drugs throughout the world (Kissin,

1982). Blum (1969) also points out that health concerns

are not necessarily the major reason for a strong social

policy regarding specific drugs.

Ray (1978) describes four pharmacological revolutions

which paved the way for the current level of illegal drug

use. Historically, drugs were part of folk remedies, reli­

gious ceremonies, and celebrations and were only available

if they were indigenous to a region. Advances in chemistry

brought about enormous changes in medicine in the 20th

century. The development of vaccines for the control of

communicable diseases represents the first of Ray's revolu­

tions. Secondly, the discovery of antibiotic drugs,

including sulfa and penicillin, made major changes in

medical care. While these two revolutions were directed at

physical health, Ray's third revolution was the use of

tranquilizers in the treatment of mental illness. "The

tranquilizers introduced to the public the concept that

drugs which act on the mind could be used to return one's

mental health to normal" (Ray, 1978, p.4). The fourth

revolution was the advent of the oral contraceptive. His

perspective is that.

For the first time potent chemicals clearly labeled as drugs are being widely used by healthy people because of their social convenience. No longer are we eliminating infection to have a healthy body, neither are we reducing anxiety to have a better functioning mind. Now we are

12

adding a drug to alter a healthy body and mind because of the convenience it offers in inter­personal contacts, (p.4)

An additional chemical push, specific to the drug under­

world, has been the development of the so called "designer

drugs" which mimic the effects of the more established

illegal substances.

Kissin (1982) discusses the effect of the 18th

Amendment on the level of drug use in the United States.

Although Prohibition was effective in reducing the con­

sumption of alcohol and the incidence of alcoholism to

levels lower than before its adoption or after its repeal,

an unexpected side effect was the development of a powerful

institution, organized crime, which continues to exert a

major force behind the availability and sale of illegal

drugs.

Discovery of indigenous substances with mind-altering

properties proceeded from accidental ingestion or inhala­

tion to intentional use in order to enhance or escape the

human condition. There were often religious connotations

to such drug use. The exact reasons for acceptance or

rejection of a particular psychoactive substance into a

culture are varied, affected by politics, economics, cul­

tural values, and sometimes by accurate information related

to drug effects. In America, the Indians used a variety of

hallucinogenic plants and tobacco was indigenous as well.

13

With the immigration of Europeans, alcohol became the drug

of choice and few other substances were widely used. This

remained the case until after World War II when the effects

of hallucinogens became widely known and their availability

to the "disenchanted youth . . . led, in the late 1950s and

1960s, to the unfolding of a drug culture so powerful that

it influenced the drug-taking pattern of the world"

(Kissin, 1982, p. 14). Since that time there has been con­

sistent movement toward increased drug use by younger age

groups involving a larger variety of illegal substances.

Adolescent Drug Use

Standard American values proscribe the nonmedical use

of drugs by youth with the exception of alcohol which the

culture perceives as a hallmark of adulthood (Jessor &

Jessor, 1975). Baumrind (1985) discusses the risk-taking

behavior which is typical of adolescent development and

that for the majority of adolescents who experiments with

drugs this behavior is self-limited to the stage of early

adolescence in which the teenager is seeking accommodation

of

Attainment of formal operational capacities; transition of conventional to principled morality; increased importance of peer relative to family as a socialization context; increased self-centeredness joined with enhanced role-taking ability; and, finally, jeopardized self-esteem, (p. 14)

14

The increased social acceptance of the recreational use of

marijuana and cocaine by adults in recent years has less­

ened the censure for involvement with these drugs. The

most common pattern of substance abuse among teenagers is

the combined use of alcohol and marijuana (Pandina & White,

1981). Patterns of drug use by nonpatient or nontreatment

populations are difficult to obtain. The typical approach

to gathering this data is a self-report questionnaire cir­

culated in public school settings. Data are also obtained

by assessing pretreatment levels of drug involvement in

patients involved in drug treatment programs. In a search

for causes of polydrug involvement by high school students,

Kamali and Steer (1976) report.

The attitudes which were related to polydrug involvement reflected a hedonistic quest for pleasant sensations and expanded creativity while simultaneously denying that drug use was potentially harmful, (p.342)

Dembo et al. (1985) discuss the sociocultural and person­

ality variables contributing to drug use. In a concept

they call "relative deviance" the authors describe the view

that for inner city urban youth, drug involvement is a

prosocial behavior and is egosyntonic while for adolescents

whose cultural values proscribe drug use, it is egodystonic

and therefore more likely to be related to psychopathology.

Hawkins, Lischner, & Catalano (1985) state that factors

such as early conduct problems predict a variety of

15

antisocial behaviors including drug abuse. These authors

review research regarding aggressiveness ratings by first-

grade teachers and low academic achievement at the end of

elementary school and find support for these issues as

predictors of delinquency and drug abuse.

The investigation becomes more complicated when

current substance use patterns are considered. Although

most studies of polydrug involvement have studied drug

preferences, there are a few which have investigated

patterns of multiple use (Kliner & Pickens, 1982).

Multiple-drug use has become the norm rather than the

exception with the combination of alcohol and marijuana

being the most common (Pandina & White, 1981; Pandina et

al. 1981). In a sample of 1,970 high school and junior

high students Pandina and White (1981) found only 6% who

reported never having used alcohol or drugs. Eighty-nine

percent of this population had tried alcohol and 74% were

current users. Fifty percent had tried cannabis and 37%

were current users. This study also included a client

population which was drawn from referrals to an agency

responsible for coordinating services for troubled adoles­

cents. Of the 224 subjects in the client group, 81% were

current users of alcohol and 66% were current users of

marijuana. Pandina et al. (1981) indicated that 41% of the

students in their survey used alcohol only, 17% used

16

alcohol and marijuana, 5% used alcohol, marijuana, and one

other drug, and 11% used alcohol, marijuana, and at least

two other drugs.

In a study of prisoners in a correctional facility for

men under 21 years of age, Marini et al. (1978) found 32.8%

of this population to be regularly using two drugs in

addition to alcohol and marijuana, 36.2% of the prisoners

were regularly using more than two drugs in addition to

alcohol and marijuana. In a study of polydrug use by high

school students Kamali and Steer (1976) found a multiple-

use pattern among 273 of 840 students. The most common use

pattern by this group was alcohol and cannabis.

The impact of drug use on children's lives can be in­

vestigated from many perspectives. In terms of prevention,

research seeks to understand the contributing factors; peer

pressure, family dynamics, preexisting genetic vulnerabil­

ity, and the effects of education programs aimed at

sensitizing children to the dangers related to drug use.

Investigations deal with the involvement of drug users in

other illegal activities and subsequently with the legal

system. Studies have also sought to correlate academic

achievement and personality factors with drug abuse.

Little attention has been directed at the cognitive

functioning of a drug abusing population of adolescents.

No studies were located which used general intelligence or

17

any cognitive measure, other than school achievement, in

assessing the characteristics of this population.

Assessment of Cognitive Functioning

Intelligence tests and other measures of cognitive

ability are based on an individual's responses to standard­

ized procedures. The results are intended to describe the

person's current functioning and to reflect potential which

may not be evident from the standardized score.

When psychologists speak of potential intelligence of a child, their interpretations are based under two categories: (1) test scatter and (2) measures of intellectual deterioration. Test scatter involves both intertest patterns and intratest variability of performances. (Magnussen, 1979, p.560-561)

A common example of the first category is a child who shows

failures on early items of a task while successfully com­

pleting later, presumably more difficult items. In this

case, interpretation of the child's performance usually in­

volves some response characteristic such as anxiety rather

than ability.

A difference between ability and potential is also

postulated in situations where the current level of func­

tioning is presumed to be lower than the level of premorbid

ability. This is the second category suggested by Magnus-

sen (1979). A clear case of this exists when there has

been a known injury to the brain. An example would be a

18

person with an injury to the left hemisphere of the brain.

In such a case, performance on measures of verbal ability

are typically uniformly low. The best measure of premorbid

language ability may be a test of oral reading. The

person's performance on such a task, which involves an

overlearned skill, is often the most accurate measure of

premorbid ability. An exception to this would be a focal

injury resulting in expressive aphasia.

A third category considered in the assessment of un-

demonstrated potential involves areas in which a child may

have lacked opportunity to develop. An example of this is

described by Kaufmann (1979) in his caution against using

instruments normed on native English speakers in assessing

the verbal ability of children who learned English as a

second language. A second example of an area of cognitive

deficit based on lack of opportunity is found in children

from backgrounds where little emphasis is placed on aca­

demic achievement. That will frequently result in the

child having a limited fund of general information even

when measures of memory are unimpaired.

After Cattell (Anastasi, 1982) introduced the idea of

describing individual differences in mental ability through

testing, assessment of intelligence began to increase in

importance as an educational and psychological tool.

Spearman reflected the generally held belief that

19

intelligence was a unitary concept and "that for the

purposes of assessing the amount of general intelligence

possessed by a person any test is as good as any other, as

long as its correlation with a is equally high" (Jackson &

Messsick, 1978, p.414). A contrasting, multidimensional

view of intelligence was proposed by L. L. Thurstone

(Guttman, 1978). This perspective on intelligence

resulted from increased sophistication in statistical

methods which allowed for analysis of commonalities and

differences among mental processes. Lezak (1983) states

that

As refinements in testing and data-handling techniques have afforded greater precision and control over observations of intellectual behavior, it has become evident that much of the behavior that tests measure is directly referrable to specific intellectual functions, (p. 21)

She describes four primary categories of cognitive ability;

receptive, memory and learning, thinking, and expressive.

In order to describe the specificity of neurological im­

pairment, Lezak provides the following example.

A brilliant research scientist was struck on the right side of his head by falling rock while mountain climbing. He was unconscious for several hours and then confused for several days, but was able to return to a full research and writing schedule shortly thereafter. On psychological tests taken six weeks after the injury, he achieved scores within the top 1-5% range on al1 tests of both verbal and visuoconstructive skills, with the single exception of a picture-arranging test requiring serial organization of cartoons into stories. On

20

this test his score, at approximately the bottom tenth percentile, was almost in the border 1ine defective ability range. He was then given a serial reasoning test involving letter and number patterns which he answered correctly, but only after taking about 25 minutes to do what most bright adults can finish in 5. He reported that his previous high level of work performance was unchanged except for difficulty with sequential organization when writing research papers, (p. 21-22)

The testing and interpretation of findings in this situa­

tion is a neuropsychological assessment. It involves an

evaluation of cognitive ability in a variety of areas to

provide a picture of current functioning. This includes

comparative strengths and weaknesses and prediction of un-

demonstrated potential and premorbid ability.

The history of neuropsychology is reported by Horton

and Puente (1986). The authors report that attempts to

localize brain deficits are recorded as early as 2500 and

3000 B.C. Paul Broca was responsible for pinpointing the

first neurological cite of a specific function with his

studies in aphasia and this work was furthered by Kurt

Goldstein's study of soldiers with traumatic head injuries.

Parallel to the work of European scientists were the

individual case studies by Russian A. R. Luria. Neuropsy­

chological assessment began as a companion to neurological

and psychiatric evaluations of patients' abilities. Much

of the early research dealt with establishing the credibil­

ity of the assessment procedures so that the tests could

21

accurately predict the cite of a lesion or trauma. With

the advent of medical technology which can provide pictures

of the brain, computed tomography (C.T.) scans, electro-

encephlagrams (EEG), and magnetic resonance imaging (MRI),

this function of neuropsychological assessment became less

important.

Despite the fact that the medical procedures could

tell the physician what the brain looked like more effect­

ively than neuropsychological tests, they could not provide

information about the functional ability of the brain. The

task of defining strengths and weaknesses and identifying

subtle forms of brain deficit remained the function of the

neuropsychologist. In addition to providing descriptive

information it is the clinician's responsibility to

(1) establish the existence of any cognitive deficits related to this insult, (2) establish the relative magnitude of this insult, (3) estimate the patient's ability to return to his previous life-style, and (4) suggest remediation programs. (Crockett, Clark, & Klonoff, 1981, p. 2)

Although neuropsychology began as an adjunct to med­

ical treatment, the research boundaries have widened so

that the techniques are currently used in assessment of

learning disabilities, personality, and behavioral disturb­

ances. Application of neuropsychological assessment to

clinical, rather than medical, populations began approx­

imately 20 years ago and there is extensive literature

22

on the effects of chronic alcohol abuse on cognitive

functioning (Parsons & Farr, 1981). Crockett, Clark, and

Klonoff (1981) cite studies using neuropsychological

evaluation in examination of delinquent behavior which

suggest that mild left hemisphere dysfunction, combined

with poor environmental controls, predict delinquency.

Dorman (1982) correlated personality and neurotic variables

of school-age boys, seven to 14 years old, with neuropsy­

chological performance and found that in the younger age

group, seven- and eight-year-olds, disorders of conduct

were related to impaired cognitive functioning. The author

posed the question of whether cognitive deficits were

manifested in extraverted, uninhibited behavior as well as

on measures of intellectual function or if certain patterns

of psychopathology negatively affect cognitive functioning.

This kind of research represents a new application of the

procedures in a field which only began at the start of the

20th century. While the potential for furthering the

knowledge of brain-behavior relationships is immense, ap­

plications of neuropsychological procedures in these areas

reach beyond the traditional use of the techniques. This

study involves such an expansion of these psychometric

techniques in evaluating the effects of polydrug use on

cognitive functioning.

23

Cognitive Functioning of Polydrug Users

The clinical impression of the "burned-out" drug user

and information regarding the powerful mind-altering

properties of drugs have raised the question of possibly

diminished cognitive capacity, either long-term or with a

very slow rate of recovery. The effects of chronic alcohol

use are well documented and are reflected in deficits in

brain functioning. The most dramatic picture of alcohol-

related dysfunction is presented in the Wernicke-Korsakoff

Syndrome. This is an amnestic syndrome resulting from

chronic alcoholism and the nutritional deficits which

accompany it. The more ubiquitous disability associated

with chronic alcohol abuse is poor adaptive functioning.

Two areas of cognitive deficit, abstract reasoning and

complex perceptual motor ability, are consistently reported

in the research on the neuropsychological functioning of

alcoholics (Kleinknecht & Goldstein, 1972).

In review of the literature examining the effects of

heavy drug use on neuropsychological test performance

Parsons and Farr (1981) and Grant and Mohns (1975) found no

evidence of cognitive deficits resulting from prolonged

heavy drug use except during intoxication. Their reviews

included studies on marijuana, sedatives, stimulants,

hallucinogens, and narcotics. These studies were inves­

tigations of the abuse of a single category of drug.

24

Grant et al. (1978) state that

. . . It is no longer meaningful to describe North American drug abusers simply as "marijuana users" or "stimulant abusers" since there is every likelihood that such groups will also have substantial experience with alcohol, sedatives, tobacco, and perhaps opiates. (P.1063)

Rather, a pattern of simultaneous or sequential abuse of

drugs was found to be typical of persons heavily involved

in drug-taking. Simultaneous use indicates involvement.of

more than one drug category in order to obtain a certain

desired result. Sequential use indicates involvement of

more than one drug category in sequence in order to

counteract or enhance the effects of the first drug.

Neuropsychological assessment of this population revealed

organic impairment in subjects with heavy, multiple-drug

use histories.

Parsons and Farr (1981) discuss the difficulty of

assessing the cognitive effects of drug usage in polydrug

abusers. Evaluation of this group presents significant

confounding variables to an understanding of the observed

deficits. Poor nutritional intake, psychopathology, head

injuries related to intoxication and the relative con­

tribution of various drug categories are all possible

contributors to the cognitive impairment. The fact appears

to be, however, that the real world presents a population

in which arbitrary distinctions are difficult to justify

and may not exist.

25

In one of the first studies to address the possible

chronic, deleterious effects of polydrug abuse on intel­

lectual and cognitive functioning, Bruhn and Maage (1975)

studied 87 men in the state prison system of Denmark. The

subjects were separated into four categories of drug in­

volvement based on responses to a clinical interview

covering drug history; 1) no drug experience; 2) marijuana

and hallucinogens; 3) marijuana, hallucinogens, and amphet­

amines; and 4) marijuana, hallucinogens, amphetamines, and

narcotics. The subjects were administered the WAIS and

measures of abstract reasoning ability, learning and memory

tests, auditory perception, analysis of complex designs,

and a continuous reaction time test. The authors found no

difference between controls and drug users, or among cat­

egories of drug users on any measure of cognitive ability.

In their review of these findings. Grant et al. (1976)

suggest that lack of discriminate results may have been due

to the statistical analysis of differences on each assess­

ment procedure rather than analysis of response patterns

which is the clinical method of determining deficit from

premorbid functioning.

In a second pioneering study, Adams et al. (1975)

completed neuropsychological evaluation of 51 polydrug

users in a Detroit treatment center. This was an inpatient

study and the initial assessment with an expanded Hal stead-

26

Reitan battery was completed within three days of

admission. A repeatable portion of the battery was admin­

istered three times; approximately one week after initial

assessment, at the end of the first month of hospitaliza­

tion, and at discharge. The average age of the population

was 26.7 years with 11.8 years of education. A comparison

of the individual procedures to normative data showed the

polydrug population to be functioning in the impaired range

on all measures except one (Trail Making Test, Part A).

The subjects of the Adams et al. study were compared to

data provided by the San Diego Polydrug Study Unit on nor­

mals, general medical patients, and neurological patients,

matched for age and education. The results showed no sig­

nificant differences between the polydrug subjects and the

neurological patients with the exception of one procedure.

The performance of the polydrug group was poorer than the

normals on eight measures (Category, Speech, Tapping with

both hands. Trails A, Trails B at the P<.05; grip strength

with both hands at the P<.001 level; and Rhythm at the

P<.01 level). These findings describe the cognitive func­

tioning of the polydrug users as similar to patients with

identified neurological impairment. The authors did find

improvements on the repeatable measures battery but were

unable to rule out the possibility that these were due to

practice effects and learning.

27

Adams et al. (1975) completed a cluster analysis on

the data from their polydrug subjects and found two

patterns of performance. For one group. Performance IQ

exceeded Verbal IQ by 12 points. This group included no

high school graduates and the subjects produced poor scores

on measures of academic achievement. This group was

younger, had more failures on tasks involving receptive

language and reported using fewer categories of drugs but

using these heavily. The authors suggest

For the group [cluster 1], there is a clear superiority in performance IQ. In investigating the subjects who could be classified into the group we found that 1) No subject in the cluster had finished high school 2) All achievement scores (WRAT) were uniformly low 3) Performance IQ was an average 12 points better than verbal IQ 4) The groups reported using fewer kinds of drug more intensively 5) The group tended to be younger than the rest of the sample and 6) More receptive language errors were present in the testing records, (p. 159)

The subjects in the second cluster had better academic re­

cords. They reported using a wider variety of drugs but

less heavily "tending to use barbiturates and narcotics,

rather than marijuana, amphetamines, or the heavier hallu­

cinogens" (Adams et al., 1975, p. 159). The second group

also showed more psychopathology based on the MMPI

profiles.

A preliminary study by Grant et al. (1976) investi­

gated the long-term cognitive effects of heavy polydrug

use. The authors compared the performance of 22 young men

28

who were admitted to a residential treatment program for

youthful narcotics addicts. The subjects were assessed at

a mean of 60 days after admission in order to minimize

toxic and withdrawal effects on the testing. The Halstead-

Reitan neuropsychological battery was administered. The

results were compared to matched groups of medical patients

and neurological patients. Each profile of test results

was submitted to an experienced neuropsychologist for

rating in one of two categories, normal or abnormal. The

findings indicated that half of the polydrug subjects were

functioning in the impaired range of mental ability. In­

dividual measures on which they performed more poorly

included Performance IQ, Full-scale IQ, Picture Completion,

and Object Assembly on the WAIS; Category Test; nondominant

time on TPT; and time for both hands on the TPT. The drug

users performed better on the Rhythm Test than the medical

controls. The investigators were unable to establish a

specific pattern of drug use relative to neuropsychological

results.

Another question explored by the authors was the

relationship of a history of head injury to cognitive

functioning. A high incidence of head injury for heavy

drug users is revealed in medical histories which include

numerous falls and motor vehicle accidents related to

intoxication (Parsons & Farr, 1981). This study did not

29

support such a relationship in their small subject

population. Further, the authors did not find that

psychiatric illness was related to cerebral dysfunction.

The investigators discuss their results very cautiously,

stating that "Those individuals who demonstrate neuropsych­

ological abnormality, according to our evaluation of these

tests, would be said to have mild, generalized cerebral

dysfunction" (p. 977). They also state that the possi­

bility of a lower level of premorbid functioning could not

be entirely ruled out.

Following these efforts, a collaborative study

supported by the National Institute of Drug Abuse was es­

tablished. Eight polydrug treatment centers participated

in an investigation of the neuropsychological performance

of their patients. In the studies by Grant and his asso­

ciates (Grant & Judd, 1976; Grant, Adams, Carlin, Rennick,

Judd & Schooff, 1978; Grant et al., 1978b) 37% of their

population scored in the impaired range on neuropsych­

ological measures. The subjects were 151 persons seeking

treatment at one of the designated centers. The comparison

group was 59 volunteers who were screened for demographic

similarities to the drug abuse group. The assessment

included administration of the Halstead-Reitan battery

initially and at a three-month follow-up.

30

In these studies, evaluation of cognitive deficits was

based on the clinical judgment of a neuropsychologist's

rating of the individual profiles in one of six categories

Better than average performance; average performance; borderline, atypical, but not clearly deficient performance; mildly impaired performance; moderately impaired performance; and severely impaired performance. (Grant et al., 1978b)

The relationship of drug use to neuropsychological perform­

ance was evaluated by multivariate analysis of variance

(MANOVA), with group membership and clinical rating of im­

pairment as independent variables. The results indicated

that heavy use of CNS depressants and opiates was related

to increased neuropsychologial impairment. Factor analysis

of the assessment instruments resulted in four factors 1)

general verbal intelligence, 2) a nonverbal factor involv­

ing visual motor, tactual, and perceptual skills, 3) simple

language perception and psychomotor speed, and 4) motor

strength. The polydrug group scored poorer than normals on

factors 1, 2 and 4. Reanalysis of the data, controlling

for the contribution of education, removed verbal intelli­

gence, factor 1, from the Main Effects. The authors felt

that the error variance involved in factor 4, grip

strength, and its small contribution to the overall solu­

tion hindered interpretation of this factor. The final

result was the finding that both the psychiatric group and

the polydrug group performed significantly (fi<.01) poorer

31

on the nonverbal measures (WAIS-R: Digit Symbol, Picture

Completion, Block Design, Picture Arrangement, Object

Assembly and on the TPT: memory and location).

The interpretation of these data is problematic,

however, due to the difficulty in distinguishing cognitive

deficits based on drug use and deficits based on serious

psychopathology. In the Grant et al. study (1978b), 26% of

a matched psychiatric population scored in the impaired

range as well. Parsons and Farr (1981) note two factors

which complicate an understanding of the data on the

effects of polydrug use,

To separate neuropsychological impairment due to prolonged polydrug use from that associated with more serious psychopathology remains a pressing problem in this research. Second, and perhaps related to the life-style and the psychopatho­logy issues, these investigators [Grant et al.] also noted that polydrug abusers, as a group, report greater instance of traumatic head injury (23%) and severe headache (28%) than either psychiatric control or nonpatient control group, (p.348)

Grant and his associates answer this issue by describing

the research on the Halstead-Reitan battery with schizo­

phrenics (Lacks et al. 1970; Klonoff et al. 1970). They

indicate that persons diagnosed as schizophrenic account

for most of the variability in the psychiatric control

group and that only three of their polydrug subjects were

diagnosed as schizophrenic.

32

In concluding their findings Grant et al. (1978b)

state.

It is striking that among the polydrug abusers, only depressant and opiate drugs could be related to observed impairment. . . . We interpret our data and previous reports to suggest that heavy, persistent amphetamine use is not related to neuropsychological impairment in most youthful users, although a few persons might indeed be at risk for idiosyncratic reasons (e.g., preexisting hypertension, vasculitis, or allergic diathesis) yet to be determined, (p. 1071)

They also indicate, based on the three-month follow-up

testing, that the deficits apparent at initial testing

showed little reversibility. They discuss the implications

for the treatment of patients experiencing cognitive

deficits and suggest that these patients should be directed

toward

Highly structured, practically oriented inter­ventions in which communications are simple and straight forward than to therapies producing high emotional arousal (and further neuropsychological disorganization), such as encounter groups." (Grant, Adams, Carlin, Rennick, Judd, & Schooff, 1978, p. 183)

In response to contradictory findings regarding the

cognitive effects of inhalant abuse, Korman et al. (1981)

studied 68 inhalant-abusing and 41 other-drug-abusing

adolescents. All of the subjects were classified as poly­

drug users and were given a neuropsychological battery.

Analysis of covariance revealed a main effects difference

between the two groups. The inhalant abusers performed

significantly more poorly (p<.05) on 20 of the individual

33

assessment procedures. The finding of impairment on both

global and specific measures of ability led the authors to

conclude that the deficits represented diffuse brain

impairment. Although the authors did not apply clinical

impairment ratings to the polydrug subjects, scores on the

20 measures showing significant differences were provided.

Application of clinical ratings to these scores describes

the inhalant abusers as functioning in the moderate range

of impairment while the polydrug subjects' functioning

appeared to be in the mild range of impairment suggesting

that the entire population of this study showed diffuse

brain dysfunction with greater impairment by the adoles­

cents emphasizing inhalant abuse.

Although neuropsychological assessment of cognitive

functioning appears to be a fruitful approach to describing

certain clinical groups there are methodological problems

which must be acknowledged. When comparing cognitive var­

iables, issues such as age, education, and socioeconomic

status (SES) are known to have effects on scores. Parsons

and Farr (1981) describe the "thorny, but unavoidable

issue" (p. 347) of general intelligence. There are two

aspects to the issue of general cognitive ability. First,

if groups are to be judged as equal for comparative

purposes the equality of ability should be a premorbid

measure. Second, the authors state that if the subjects

34

are pulled from a population with higher levels of general

ability, such as college students, their abilities may be

resistant to demonstrating deficits as measured by neuro­

psychological instruments. General intellectual ability is

highly positively correlated with the outcome of cognitive

functioning subsequent to brain injury. Symonds (as cited

in Lezak, 1983) states "It is not only the kind of injury

that matters, but the kind of head."

Reliable measures of premorbid ability are difficult

to obtain because few subjects would have received assess­

ments previous to the development of the clinical concern.

Lezak (1983) reports two methods of estimating premorbid

ability. It should be noted that she is discussing these

variables as they relate to assessment of individual

patients, not groups. One method involves choosing a

cognitive measure which has been shown to be resistant to

the effects of brain damage and using this as a benchmark

against which to evaluate all other performance. The

Vocabulary and Picture Completion subtests of the Weschler

scales and reading test scores from academic achievement

measures are often used because of the supposed resistance

of old, overlearned skills to the effects of cognitive

dysfunction. These measures are not usually thought to be

accurate predictors of premorbid ability in patients with

left hemisphere damage.

35

Summary and Review of Hypotheses

The review of the literature establishes the

impairment of cognitive functioning as the result of poly­

drug use involving certain categories of drug use. In the

best controlled, most extensive of these studies. Grant et

al., 1978b, the findings suggest that areas of dysfunction

involve nonverbal ability in visual-spatial, tactual-

spatial and visual-perceptual areas. These are the areas

commonly thought to be most sensitive to brain impairment.

These deficits were found in polydrug abusers involved with

depressants and opiates. Other drug categories were not

related to observed impairment. The subject populations in

the preceding research were young adults. Demographic

research regarding drug use indicates a continued downward

trend in age in the use of drugs and establishes the norm

of polydrug usage in those adolescents using drugs.

As the result of this review of the literature the

pertinent question regarding the cognitive functioning of

adolescent polydrug users is whether they exhibit cognitive

deficits relative to performance on neuropsychological

assessment procedures. In order to respond to this

question the following hypotheses will be investigated:

Hypothesis 1. Adolescents in a drug addiction

treatment program will demonstrate cognitive functioning

on neuropsychological measures of brain function which

36

will not significantly differ from adolescents who are

neurologically impaired.

The suggestion that the cognitive ability of polydrug

abusing adolescents will resemble that of neurologically

impaired teenagers is supported by the findings of Adams et

al. (1975) and the results of the national collaborative

study directed by Igor Grant (Grant, Adams, Carlin,

Rennick, Judd, & Schooff, 1978; Grant et al., 1978; Grant

& Judd, 1976, Grant et al., 1976) in which polydrug users

in their early 20's were found to experience "mild

generalized cerebral dysfunction" (Grant et al., 1976, p.

977).

Hypothesis 2. Adolescents in a drug addiction

treatment program will demonstrate cognitive deficits on

neuropsychological measures of brain function based on a

clinical pattern analysis of an experienced neuropsych­

ologist.

Grant et al. (1978b) used clinical assessments of

experienced neuropsychologists as the best measure of

levels of deficit. They recommend this procedure because

the mean scores of groups are not reflective of the func­

tioning of the individual and because analysis of the

pattern of performance, relative strengths and weaknesses,

is the clinical basis of assessing neuropsychological

deficit. This hypothesis suggests that if the pattern of

37

cognitive performance by the polydrug abusing adolescents

looks like that of someone who has impaired functioning

then their ability can be described as impaired.

CHAPTER III

METHODOLOGY

The review of the literature related to adolescent

drug use and the possibility of related cognitive deficits

suggests several areas for investigation. As the result of

previous research findings the current investigation was

proposed to test the hypotheses presented in the previous

chapter. This chapter describes the research design,

methodology, and analysis of the data.

Subjects

The polydrug subjects of the study were inpatients at

a private psychiatric hospital in a southwest community.

Participation was voluntary and involved signed permission

by the patient, the parents, and the attending physician.

Initial screening was done to determine if there was

evidence of acute neurological impairment such as previous

head trauma, acute or chronic physical disease, gross

psychopathology such as psychosis or schizophrenia, and

sensory or motor deficits which would impede the subject's

performance of the test battery. No subjects were excluded

from the study for these reasons. Detoxification of the

subjects was assessed through evaluation of medical staff

based on urine drug screening and the subjects' behavior.

38

39

The patients at the hospital represent the middle and

upper-middle socioeconomic strata.

The determination of substance addiction for the

inpatient population was based on the admitting diagnosis

of the attending physician in compliance with the defini­

tion of "substance addiction" of the hospital. These

criteria were consistent with the Diagnostic and Statis­

tical Manual of the American Psychiatric Association

(1980).

The second group of subjects were adolescents who had

been evaluated subsequent to significant neurological

trauma. Their neuropsychological testing was conducted as

part of the routine medical follow-up in order to assess

cognitive functioning and to develop recommendations for

treatment.

Instruments

Demographic and Background Data

Medical History

The Medical History Questionnaire (Grant, Adams,

Carlin, Rennick, Judd & Schooff, 1978) evaluates the pres­

ence of trauma or illness which could account for abnormal

neurological findings. This questionnaire was used with

the polydrug subjects to assess medical events which might

40

establish prior cause for the existence of neurological

dysfunction. (See Appendix A.)

Demographic Data

Following the recommendations of Gersick et al. (1980)

the demographic data covered age, sex, socioeconomic

status, religion (denominational affiliation and degree of

religiosity), level of academic achievement, race and

ethnicity. Through the interview with this instrument the

polydrug subjects also reported information on peer,

family, and community variables. The demographic question­

naire appears in Appendix B.

Psychological Functioning

The Minnesota Multiphasic Personality Inventory (MMPI)

(Hathaway & McKinley, 1967) is the most commonly admin­

istered objective personality instrument. This inventory

is completed by all adolescent inpatients at the psych­

iatric hospital. The inventory consists of 566 true-false

questions. The responses are then scored on 10 clinical

scales describing major classifications of psychopathology.

Four validity scales are included which evaluate the

subject's attitude toward the test. This instrument is

criterion referenced so that responses are compared to

responses of criterion groups such as hypochondriacal and

psychopathic deviance. As Anastasi (1982) points out, one

41

weakness of the MMPI is that each scale was developed by

comparing the criterion group to the normative sample

rather than criterion groups to one another. High cor­

relations among the diagnostic scales call into question

their ability to differentiate among diagnostic categories

(Anastasi, 1982). Retest reliability is reported to range

between .50 to the low .90's (Hathaway & McKinley, 1967).

A particular difficulty arises with application of the MMPI

to the special population of this study. Adolescent norms

are available (Green, 1980) but adequate interpretation of

the findings is still uncertain. Green (1980) suggests

the use of adult interpretive data based on adolescent

norms. This is the format which was used in this inves­

tigation.

The Beck Depression Inventory (BDI) (Beck & Steer,

1987) is a widely used instrument in quantifying depressive

symptoms in adults and adolescents. It is a self-report

questionnaire of 21 items to which the person responds on a

four-point Likert scale. Interpretation of the scores is

based on total points and evaluation of critical items

relating to suicidal ideation and hopelessness. The manual

suggests the following guidelines for evaluating individual

scores:

Scores from 0 to 9 are considered within the normal range or asymptomatic; scores of 10 to 18 indicate mild-moderate depression; scores of 19 to 29 indicate moderate-severe depression;

42

and scores of 30 to 63 indicate extremely severe depression, (p. 7)

Test-retest administrations of the BDI in clinical

populations should reflect improvement after exposure to

therapeutic treatment and therefore reliability coeffi­

cients vary depending on the population. Test-retest

correlations for psychiatric patients ranged from .48 to

.86 while studies of nonpsychiatric patients ranged from

.60 to .90. With regard to content validity the scale

reflects the diagnostic criteria associated with depres­

sion in the DSM-III with the exception of symptoms which

were felt to produce a high number of false positives. The

authors indicate that discriminant validity has been shown

by the BDI ability to discriminate among diagnostic catego­

ries. Construct validity has been evaluated against the

concept of hopelessness through the Beck Hopelessness

Scale and has been found positively related to the BDI.

The BDI has been assessed for concurrent validity with the

MMPI-D Scale, Zung Self-rating Depression Scale, psych­

iatric ratings and correlations range from .55 to .73 (Beck

& Steer, 1987).

Measures of Cognitive Ability

Successful performance of a cognitive task is the re­

sult of the ability to execute the components which make up

that task. Poor performance may be the result of the loss

43

of one contributing skill and not others. Not all

investigators agree about the primary and secondary abil­

ities on cognitive tasks. This is clearly seen in the

three most popular classification systems for the WISC-R.

Kaufmann (1979) discusses his factor analytic studies,

Bannatyne's recategorization system, and Guilford's

structure-of-intellect model and describes the varying view

which each approach takes regarding the underlying abil­

ities of the subtests of this instrument.

There are also broad theoretical differences regarding

the way in which the brain functions. The most widely

accepted approach to understanding brain-behavior rela­

tionships in the Western world is the lateralization of

function theory. In this theory language-analytical skills

are thought to be the function of the left hemisphere of

the brain while spatial-intuitive skills are the function

of the right hemisphere. This view will be followed in

interpretation of the test data in this study because the

related literature used this approach and therefore it

provides the most comparative data. Further, the

descriptions of patterns of cognitive ability, relative

strengths and weaknesses, will follow this approach and are

consistent with the interpretations of Reitan and Wolfson

(1985) and Lezak (1983).

44

General Intellectual Ability

The age-appropriate form of the Wechsler scales was

used as a measure of the general intelligence of the sub­

jects. The results on the WISC-R and WAIS-R provide the

basis from which all major neuropsychological test bat­

teries proceed (Lezak, 1983). The Full Scale IQ and the

Verbal and Performance IQ's are used extensively in edu­

cational settings to estimate academic functioning. In

neuropsychological assessment of cognitive ability the

subtests of the Wechsler scales are typically evaluated

individually according to the components of ability thought

to affect performance. Split-half reliability for the

three global intelligence measures are .97, .93, and .97

for Verbal, Performance, and Full Scale IQs, respectively,

for the WAIS-R and .94, .90, and .96 for the WISC-R

(Wechsler, 1974; Wechsler, 1981). Both versions of the

Wechsler scale have been found to have high correlations

with academic achievement and with the Stanford-Binet.

Academic Achievement

The Wide Range Achievement Test - Revised (WRAT-R)

(Jastak, Bijou, & Jastak, 1984) was administered to assess

the subject's level of academic achievement in the tradi­

tional areas of spelling, reading, and math calculation.

Test-retest reliability was determined from the normative

45

group. For the ages included in the study the results were

.90 for reading, .89 for spelling, and .79 for arithmetic.

The content validity of the subtests is clear in that they

are meant to measure basic academic skills. Item diffi­

culty was determined by the Rasch method of mathematical

analysis of ability and difficulty and indicated that the

item reflects a full range of difficulty. Construct valid­

ity is supported by the high item separation reliability

coefficients which indicates that the measures are sensi­

tive to developmental changes across the ages included.

Concurrent validity reflects that the WRAT-R is comparable

to other achievement measures with correlations in the high

.60's, .70's, and .80's (Jastak, Bijou, & Jastak, 1984).

Memory and New Learning

The Auditory-Verbal Learning Test (AVLT) (cited in

Lezak, 1983) is used to assess the subject's ability to

learn new verbal material. A series of 15 words is pre­

sented orally by the examiner after which the subject is

requested to say as many as are remembered. The list is

presented four additional times to assess the efficiency

and rate of learning. Reliability information was un­

available on this instrument. Concurrent validity was

supported by the finding that recall of the number of words

on the AVLT is similar to that of digits forward of the

46

Wechsler Digit Span subtest. Miceli et al. (1981) found

that a modification of the AVLT discriminated well between

patients with right and left hemisphere lesions.

Visual-Spatial and Visual-Perceptual Ability

The Complex Figure Test (CFT) (cited in Lezak, 1983)

is a complex visual-perceptual drawing task which includes

a recall trial. The subject is presented a design and

asked to reproduce it on a blank sheet of paper. Erasures

are permitted. The subject is not informed of the recall

trial of the task. After an intervening and cognitively

unrelated task, the subject is asked to draw the figure

from memory. The task assesses visual-spatial perception,

organization of complex visual information, and visual

memory. No reliability information was available on this

instrument. Discriminant validity is suggested by the

consistent ability of the figure drawing to differentiate

between localized lesions (Lezak, 1983).

Higher Conceptual Processing

The Wisconsin Card Sorting Test (WCST) (Heaton, 1981)

was selected to assess abstract reasoning ability. This is

a deductive reasoning task which requires the subject to

identify simple categories and develop and maintain correct

response sets based on feedback from the examiner. The

47

subject is given two decks of 64 cards each and asked to

match each of the cards to one of four key cards (marked

with one red triangle, two green stars, three yellow

crosses, and four blue circles). The subject's cards vary

randomly on color, number, and shape. The principle of

correctness is established by the examiner and must be

deduced by the subject by the "correct" or "incorrect"

verbal feedback provided by the examiner to each attempted

match. After the subject has made 10 consecutive correct

responses, the examiner shifts to another sorting

principle. Problems on this instrument can come from

difficulty identifying the categories, perseveration to an

incorrect category, or shifting to an incorrect category

before the criterion is met. No reliability information

was available on this instrument. Construct and discrim­

inant validity are supported by high correlations with the

WAIS Full Scale IQ and the Halstead-Reitan Battery Average

Impairment Rating when normals and brain damaged patients

were compared.

Attention and Concentration

The Trail Making Test combines two parts which assess

visual scanning and complex attentional functions. On Part

A the subject is required to connect "as quickly as he

can," in consecutive order, a set of circled numbers. On

48

Part B the subject must perform the same task but alternate

between numbers and letters (e.g., 1-A-2-B). Digit Span

would be an example of the simplest task of attention and

recall, while Part B of the Trail Making Test is a complex

task of visual tracking, conceptual tracking, and ability

to shift response sets appropriately (Lezak, 1983). Lezak

(1983) found test-retest coefficients of .78 for Trails A

and .67 for Trails B. The author found significant

(e<.001) practice effect on Trails A while Trails B did not

improve significantly.

Design and Analysis

The results of the performance of the polydrug group

were compared to a matched sample of neurological patients.

The t-test was used to statistically evaluate these

comparisons.

The data were reviewed by a certified psychologist

with clinical training and three years experience in

neuropsychological assessment. The clinician rated the

subject's performance on a six-point scale ranging from

above average ability to profound cognitive impairment.

The rater was blind to the subject's group membership and

reviewed the pattern of performance to determine the im­

pairment rating. In the analysis of these data the first

three categories (above average, average and mildly

49

impaired) were classified as "unimpaired" with the

remaining three categories (moderately, severely, and

profoundly impaired) classified as "impaired." This

grouping is consistent with the procedures used in the

national study by Grant, Adams, Carlin, Rennick, Judd,

Schooff, et al. (1978). The t-test was used to provide a

comparison of the performance rating of the polydrug and

the neurological groups.

The independent variables were group membership with

the dependent variables being the cognitive measures and

the overall impairment ratings.

Procedures

The investigator administered the age appropriate

Wechsler scale and the neuropsychological procedures. Each

subject was told that participation was voluntary and would

not affect the course of treatment and that consent could

be withdrawn at any time. The researcher chose to admin­

ister the cognitive instruments in the same order to all

subjects. An alternative would have been to systematically

vary the presentation. Varying the instruments would have

controlled for fatigue and motivation factors. This was

not done, however, so that the results would provide the

most valid comparison to the findings of the neurologically

50

impaired subjects who had been previously tested in that

format.

The medical history questionnaire and the demographic

information were obtained during an interview with the

subject at the time of the testing. The MMPI and BOF were

administered by hospital personnel as part of its asses­

sment procedures. The standard format at the hospital

involved the use of a computer administration and analysis

of the responses on the MMPI.

Due to the schedule of therapeutic activities in which

the polydrug subjects were involved, their testing was

typically completed during two sessions on consecutive

days. The total time required for administration of the

battery was approximately five hours. This did not include

completion of the MMPI which was scheduled by the hospital.

The testing of the neurologically impaired subjects was

typically done within the same day with three hours of the

testing completed in the morning, a break for lunch and the

remaining two hours completed in the afternoon.

The data on the neurological subjects represented

patients who had been tested over the previous five years.

The evaluations had been completed by the staff of a

rehabilitation facility in the same community as the

hospital. When multiple assessments on a patient were

available, the most recent one was chosen in order to

51

reflect a stable picture of the patient's ability and to

minimize the acute disorienting effects of the injury on

the test results.

The clinical rater had no prior knowledge of the

subjects. The data on each individual's performance was

presented on a summary sheet on which there was no

identifying information.

CHAPTER IV

RESULTS

This study was a comparison of two groups of adoles­

cents on measures of cognitive ability. One group was

receiving inpatient treatment in a psychiatric hospital

related to substance abuse. The other group was comprised

of adolescents with medically substantiated neurological

impairment related to closed head injuries or neurosurgery.

The neurological subjects were tested over a three-year

period of time in a rehabilitation center. The performance

of all subjects was compared to available normative data.

The purpose of the study was to determine if adolescent

polydrug abusers would show cognitive deficits on neuro­

psychological measures which are commonly used to determine

functional ability after neurological trauma.

Descriptive Data

Subjects

The subjects studied were 31 adolescents, 16 polydrug

abusers and 15 teenagers with a history of neurological

trauma. Their ages ranged from 12 to 19 years with a mean

age of 16.7 years. The subjects in the drug group were

somewhat younger than in the neurological group but the

differences were nonsignificant, t(29)=-0.76, fi<.45. There

52

53

were 22 Anglos and nine Hispanics. The subjects comprised

two intact groups, polydrug abusers and neurologically im­

paired. Table 1 presents this information for each group.

Demographics on Polydrug Subjects

Demographic information on the polydrug subjects was

collected by the examiner in an interview at the time of

the testing. Corresponding data on the neurologic group

were unavailable because they were tested prior to the

initiation of the study. Typical subjects from the poly­

drug group were Protestant and described themselves as

mildly religious. The middle class socioeconomic strata

predominated. Nine of the 16 subjects reported a per­

ception of having sustained cognitive impairment as the

result of drug use. Areas of perceived impairment included

memory loss and slowed reaction time. The age of the

subjects at the first exposure to drugs ranged from seven

to 16 years (M = 10.31, SD = 4.49). The duration of drug

use ranged from one to nine years (M = 4.31, SD = 2.28).

Thirteen of the subjects (81.4%) reported a parent or

grandparent with a history of alcohol or drug addiction.

One subject who reported no addiction problem in this group

of relatives was adopted and had no information about the

biological parents. Ten of the 14 subjects with siblings

54

TABLE 1

DEMOGRAPHIC CHARACTERISTICS OF ALL SUBJECTS

Item

Number

Age

M

SD

Grade

M

SD

Sex

Male

Female

Race

White

Nonwhite

Polydrug Users

n

16

16.19

1 .5

9.63

1 .54

8

8

10

5

Neurologically Users

n

15

17.19

3.18

10.07

2.23

12

3

12

4

55

(71.4%) reported a sibling with an addiction problem. Ten

of the subjects had been arrested in connection with their

drug use. These data plus marital history and educational

history of the parents are reported in Table 2.

Medical History of the Polydrug Subjects

Information from medical histories was used in as­

sessing the polydrug subjects' neurological background to

determine if exclusion from the study was necessary. Four

of the subjects did have histories of minor head injuries

related to falls and motor vehicle accidents, none of these

injuries had resulted in loss of consciousness. Seven

subjects reported having experienced loss of consciousness

related to drug use and eight indicated having been under

general anesthesia for surgeries such as tonsilectomies.

Eleven subjects indicated that they experienced frequent

headaches and eight reported having been diagnosed with

learning disabilities. These data are reported in Table 3.

Categories of Drugs Used

The frequencies of involvement with differing cat­

egories of drugs are presented in Table 4. This group of

adolescents was heavily involved in stimulant and marijuana

use (87.5%). Alcohol use was third highest with 68.8%.

Only two subjects listed no stimulant use. The two

TABLE 2

DEMOGRAPHIC VARIABLES OF THE POLYDRUG GROUP

56

VARIABLE n % VARIABLE n

LIFE SATISFACTION

1 - 3

4 - 6

7 - 1 0

8

SOCIOECONOMIC STATUS

Lower class

Divorced

Widowed

31.3

50.0

18.8

12.5

Middle class 12 75.0

Upper class 2 12.5

PARENTS' MARITAL STATUS

Married 6 37.5

43.8

18.7

QUALITY OF PARENTS' MARRIAGE

Close and Warm 10 62.5

Cold and distant

Angry and Hostile

31.3

6.3

PERCEPTION OF IMPAIRMENT

No

Yes

RELIGIOUS PREFERENCE

Protestant

Catholic

Other

10

EXTENT OF RELIGIOUS FEELING

Strongly

Moderately

Fairly

Mildly

Very Little

Not at all

0

3

4

5

3

0

40.0

60.0

66.7

13.3

20.0

0.0

20.0

26.7

33.3

20.0

0.0

57

TABLE 2 - Cont inued

VARIABLE

MOTHER'S EDUCATION

Less than high school

High school

Some College

College Graduate

Post graduate work

n

0

11

4

0

1

AGE FIRST USED DRUGS

7

8

9

10

12

13

14

15

16

1

1

2

1

6

1

2

1

1

%

0.0

68.8

24.0

0.0

6.3

6.3

6.3

12.5

6.3

37.5

6.3

12.5

6.3

6.3

VARIABLE

FATHER'S EDUCATION

Less than high school

High school

Some college

College graduate

Post graduate work

FAMILY HISTORY OF ALCOHOL DRUG ADDICTION

Father

Mother

Paternal Grandfather

Paternal Grandmother

Maternal Grandfather

Maternal Grandmother

Total subjects with first degree relative with history of addiction

n

3

8

3

2

0

OR

10

1

9

1

8

• 1

13

%

18.8

50.0

18.8

12.5

0.0

62.5

6.3

56.3

6.3

50.0

6.3

81.4

SIBLING HISTORY OF ALCOHOL OR DRUG ADDICTION

Yes 10 62.5

No 37.5

58

TABLE 3 MEDICAL HISTORY QUESTIONNAIRE

QUESTIONS n %

Difficult maternal pregnancy

Premature birth

Subject required postnatal observation

Subject hospitalized before age 6

Febrile convulsions (without other disease) 1

Learning difficulties in school

Traumatic head injury

Posttraumatic amnesia

Nontraumatic unconsciousness

Diagnostic brain tests

History of neurological disease

Epilepsy

Overdose requiring hospitalization

Severe headaches

Frequent muscular weakness

Numbness of extremities

Frequent faintness or dizziness

General anesthesia

1

0

0

2

1

8

4

1

7

3

0

0

4

11

6

5

6

8

6 . 3

0 . 0

0 . 0

1 2 . 5

6 . 3

5 0 . 0

2 5 . 0

6 . 3

4 3 . 8

1 8 . 8

0 . 0

0 . 0

2 5 . 0

6 8 . 8

3 7 . 5

31 . 3

3 7 . 5

8 0 . 0

59

TABLE 4

CATEGORIES OF DRUGS USED

DRUG

Marijuana

Stimulants

Cocaine

Oral stimulants

Intravenous stimulants

Alcohol

Hallucinogens

Depressants

Narcotics

Inhalants

n

14

14

11

7

2

11

4

3

3

2

%

87.5

87.5

68.8

43.8

12.5

68.8

25.0

18.8

18.8

12.5

60

subjects involved in intravenous use of stimulants reported

injections every four to six hours through the day. One

subject, however, reported alcohol as the primary drug of

choice.

Psychological Functioning of Polydrug Subjects

The results of the MMPI provided little information in

assessing the presence or absence of psychopathology in

this population. Only nine of the 16 subjects produced

valid results on the instrument and the hospital was unable

to locate the results on one of these patients. Two

patients could not read well enough to complete the MMPI

and were evaluated by the psychology staff of the hospital

with other measures. The remaining six subjects produced

invalid results. The validity scales suggested that the

invalid results were due to response bias reflecting random

responses, "fake bad" or "fake good" response sets.

Several of the subjects stated during the neuropsych­

ological testing that they had been unwilling to respond

appropriately due to the length of the instrument.

Eleven subjects received the Beck Depression Inventory

(M = 12.82, SD = 10.14). The results indicate that the

group fell in the lower end of the mild-moderate range of

depression.

61

Medical History of the Neurologically Impaired Subjects

The neurologically impaired group was made up of 14

victims of closed head injuries, one patient who had

neurosurgery for removal of a tumor. Cognitive data were

provided by the rehabilitation center on 21 patients. On

five of the patients raw data were unavailable and on one

patient the extent of paralysis prevented the admin­

istration of nonverbal test items. If more than one

neuropsychological battery had been administered, the most

current results were used. The length of time since the

injury or trauma ranged from one month to 10 years (M =

15.40, SD 29.54).

Clinical Impairment Ratings

The clinical ratings were categorized into six levels

of performance, above average, average, mild deficit,

moderate deficit, severe deficit, and profound deficit

based on assessment of the pattern of ability. Absolute

frequencies and relative percentages for the subjects are

presented in Table 5. These categories were collapsed into

two levels, reflecting functioning within normal limits

(above average, average, and mild deficit) and impaired

functioning (moderate, severe, and profound deficit).

Absolute frequencies and relative percentages of the

unimpaired and impaired ratings are presented in Table 6.

62

TABLE 5

FREQUENCIES OF CLINICAL IMPAIRMENT RATINGS

IMPAIRMENT RATING

Above average

Average

Mild impairment

Moderate impairment

Severe impairment

Profound impairment

POLYDRUG n %

1

5

7

2

1

0

6.2

31 .3

43.8

12.5

6.2

0.0

NEUROLOGICAL n %

1

1

7

4

2

0

6.7

6.7

46.7

26.7

13.2

0.0

TOTAL n %

2

6

14

6

3

0

6.5

19.4

45.2

19.3

9.6

0.0

TABLE 6

FREQUENCIES OF UNIMPAIRED AND IMPAIRED CLINICAL RATINGS

IMPAIRMENT RATING POLYDRUG n %

NEUROLOGICAL n %

TOTAL n %

Unimpai red

Impai red

13 81.2

3 18.8

9 60.0

6 40.0

22 71.0

9 29.0

63

Hypothesis Testing

Hypothesis 1

Hypothesis 1 stated that subjects in a drug addiction

treatment program would score no differently on neuropsych­

ological measures of cognitive ability than subjects with

medically identified neurological impairment. The hy­

pothesis was tested using a two-tailed t-test procedure

(df=29). The results reflected that the neurological 1y

impaired subjects scored significantly poorer on numerous

measures. The Digit Symbol/Coding subtest of the Wechsler

scales; Trail Making Test, Parts A and B; and the Auditory-

Verbal Learning Test, trials 5 and 6 were significant at

e<.001. Performance I.Q., Arithmetic, and Digit Span of

the Wechsler scales and perseverative responses on the

Wisconsin Card Sort were significant at fi.<.01. The Full

Scale I.Q., the Picture Completion and Block Design

subtests of the Wechsler scales and the recognition trial

of the Auditory Verbal Learning Test were significant at

fi<.05. Complete results are reported in Table 7. The data

are graphically represented in Figure 1.

Discussion of Clinical Significance of Group Means

Clinical review of individual tests and the assignment

of impairment ratings established by normative data is

64

TABLE 7

COMPARISON OF NEUROPSYCHOLOGICAL TEST RESULTS OF POLYDRUG USERS

AND NEUROLOGIC GROUPS

TEST

DRUG (n=16) MEAN

NEUROLOGIC (n=i5) MEAN

WECHSLER INTELLIGENCE SCALE

FULL SCALE IQ 97.06

VERBAL IQ 95.06

PERFORMANCE IQ 100.56

INFORMATION 7.94

COMPREHENSION 9.75

ARITHMETIC 9.00

SIMILARITIES 9.75

DIGIT SPAN 9.75

VOCABULARY 9.12

DIGIT SYMBOL 9.81

PICTURE COMPLETION 10.44

BLOCK DESIGN 10.44

PICTURE ARRANGEMENT 11.13

OBJECT ASSEMBLY 10.13

87.20

87.93

88.07

7.20

8.40

6.93

9.00

7.01

8.13

6.87

8.13

8.47

9.67

8.20

2.04

1.53

2.49

0.82

1.39

2.10

0.69

2.49

0.98

2.99

2.46

1.72

1.38

1.72

.051

.137

.019

.421

.176

.044

.494

.019

.335

.006

.020

.097

.185

.097

TABLE 7 - Continued

65

TEST

DRUG (n=16) MEAN

NEUROLOGIC (n=15) MEAN

WIDE RANGE ACHIEVEMENT TEST-REVISED

READING

SPELLING

ARITHMETIC

91.94

88.81

86.69

93.93

93.07

78.93

-0.34

-0.51

0.94

.735

.613

.353

AUDITORY-VERBAL LEARNING TEST

TRIAL 1

TRIAL 5

TRIAL B

TRIAL 6

TRIAL 5-6*

RECOGNITION TRIAL

COMPLEX FIGURE TEST

COPIED TRIAL

RECALL TRIAL

5.87

12.88

4.94

11.88

1.19

13.94

30.43

17.97

5.13

10.40

3.80

9.07

1.40

12.93

27.17

16.83

1.44

3.03

1.76

2.49

-0.43

2.09

PERCENTAGE RECALLED 58.31 59.73

1.56

0.40

-0.19

.160

.005

.088

.019

.668

.046

.130

.691

.849

* Low score represents better performance

66

TABLE 7 - Cont inued

TEST

WISCONSIN CARD SORTING TEST

CORRECT

ERRORS*

NONPERSEVERATIVE ERRORS*

PERSEVERATIVE ERRORS*

CATEGORIES COMPLETED

TRAIL MAKING TEST

TRAILS A*

TRAILS B*

DRUG (n=16) MEAN

73.06

31.44

14.25

16.06

5.25

22.38

59.38

NEUROLOGIC (11=15) MEAN

79.00

42.33

16.00

24.87

4.60

44.60

107.87

t

-1.59

-1.66

-0.55

-1.74

1.49

-4.62

-3.23

B.

.123

.108

.595

.092

.146

.0001

.003

* Lower score represents better performance

67

1000 T

100 •• e = e =

SCORES

10 ••

••- DRUG GROUP

•o-NEUROLOGIC GROUP

=^^:z^^^—t.~n—^. -o- :S^«^8

H h + H h 1 -M 1 1 1 1 1 FSIQVIOPIO I C A S DS V DSY PC BD PA OA

TESTS

FIGURE 1

COMPARISON OF GROUP MEANS FROM TABLE 7

68

1000 T

100 - 0 = 0 -

SCORES

10 ••

••- DRUG GROUP

•o-NEUROLOGIC GROUP

] - M — I — I I I — I — I I I — I — I — I — I — I — I — I — I — I — h

R S A 1 5 B 6 5/6 R C R PR C E NEPECC A B * * * * * *

VRAT AVLT CFT TESTS

VCS TRAILS

* Low score represents better performance.

FIGURE 1 - Cont inued

69

important in understanding the real significance of the

research findings in addition to the statistical signif­

icance. Without the use of available normative data and

cutoff scores for impairment indices, the meaning of the

research findings is less than clear. The most meaningful

review of neuropsychological data is clinical examination

of each individual's test results. This was done in

Hypothesis 2. At this point, however, the discussion will

involve the application of clinical impairment ratings to

the group means. This represents a loss of some descrip­

tive information but aids in analysis of the functional

ability suggested for each of the clinically identified

groups. It is important to recall from the Procedures

section that clinical ratings of performance which are

assessed as above average, average, and mildly impaired are

considered within normal limits and that dysfunctional

ability is demonstrated in moderate, severe, and profound

levels of impairment.

Table 8 reports the data for both groups in four

categories. First, there were tasks on which the neuro­

logical ly impaired group was statistically different from

the polydrug group and where this also represented a

difference between impaired and unimpaired functioning.

Second, there were tasks on which statistical differences

70

TABLE 8

COMPARISON OF STATISTICAL FINDINGS AND CLINICAL IMPAIRMENT RATINGS ON

INDIVIDUAL TESTS

Signif icant differences-neurological

group impaired

Significant differences-neurological

group unimpaired

Nonsignificant differences-neurological

group impaired

Nonsignificant differences-

both groups impaired

WAIS-A *

WAIS-DS *

WAIS-Dsym *

AVLT-5 *

AVLT-6 *«

TRAILS A *

TRAILS B *

WAIS-PC

AVLT-R

CFT-COPY **

WCS-PE **

WAIS-I *

CFTX *

WRAT-A **

* M i l d impairment

* * Moderate impairment

71

were found but where the scores of both groups fell within

normal limits. Third, there were tests on which there were

not statistical differences but on which clinical ratings

indicated impairment for the neurologic group. The final

category included two items on which there were not statis­

tical differences but where the scores of both groups fell

in the impaired range.

Subtest scores on the Wechsler scales are evaluated

against a mean of 10 and a standard deviation of 3

(Wechsler, 1981, 1974). Five subtests showed statistically

significant differences between the two groups. In the

verbal cluster of subtests. Arithmetic and Digit Span both

showed poorer performance (fi<.05) by the neurologic group.

In both instances the performance of the polydrug group was

in the average range while the neurologic group showed a

mild level of impairment on these tasks.

With the nonverbal, perceptual organization subtests.

Digit Symbol/Coding (p<.01) and Picture Completion (p<.05)

showed statistically significant differences favoring the

polydrug group. In each case their functioning was in the

average range. The score of the neurologic group on

Picture Completion fell in the low average range while

their Digit Symbol/Coding scores fell in the low average

range of ability, suggesting a mild level of impairment.

72

The differences in group performance on Trails A and

Trails B describe the polydrug group as functioning in the

average range of ability while the neurologic group showed

mild impairment on this complex task of visual attention

and motor speed. The neurologic group's performance on

these two tests and the subtests of the Wechsler scales.

Arithmetic, Digit Symbol/Coding, and Digit Span (on which

the neurologic group showed statistically significant

differences plus impairment ratings), are consistent with

findings on patients with diffuse brain damage. These

problem areas are commonly found with head injured pop­

ulations and are due to difficulty on tasks requiring

sustained attention, mental tracking, and speeded motor

ability (Lezak, 1983).

The final tasks on which the neurologic group showed

both statistically poorer performance and impairment were

trials 5 and 6 of the AVLT. Lezak (1983) suggests that the

pattern of functioning demonstrated by the neurologic group

reflects problems with new learning and retention of infor­

mation. While their immediate recall was in the normal

range, along with the polydrug group, their learning across

repeated trials was significantly poorer. Statistical

difference was found on the recognition trial as well but

the neurologic group's score was not in the impaired range.

73

The neurologic group showed moderately impaired scores

on three additional measures where statistically signif­

icant differences were not found, computational arithmetic

on the WRAT-R, the copy trial of the CFT, and perseverative

errors on the WCS. The arithmetic score is frequently

impaired in closed head injured populations. The CFT

represents a novel task which requires complex perceptual

organization and planning and is also sensitive to diffuse

brain impairment.

Perseveration is an impairment in cognitive flex­

ibility and the capacity to shift response sets as task

requirements change. The normative data on the WCS

(Heaton, 1981) reports a mean of 12.6, SD = 10.2 for per­

severati ve errors. Although these data were drawn on an

older population (M = 35.9, SD = 15.3) with high average

Full Scale I. Q. (M = 114.0, SD = 11.7), recent research

(Chelune & Baer, 1986) to establish developmental norms

found that by the age of 10 years children's performance is

comparable to adults. Using the adult norms as the inter­

pretive base for the functioning of the two groups in the

current study, the score for the neurologic group on per­

severati ve errors indicated moderate impairment.

Two tests showed no differences between the groups but

the scores for both were similar in suggesting lower levels

of functioning. Scaled scores for both groups fell in the

74

low average range for the Information subtest of the

Wechsler scales which assesses general fund of information.

Good performance on this task is contributed to by verbal

comprehension and memory (Kaufmann, 1979). Influences

which affect performance on this subtest include stim­

ulation in the child's early environment, school learning,

and intact remote memory, therefore the lower level of

functioning in this area may be accounted for in a variety

of ways. For one person it may be the result of problems

with retrieval of long-term memory while in another it may

be the result of low academic motivation. The small n in

the present study prevented factor analysis of the data to

investigate the factors which may have similarly or dif­

ferentially affected the performance of each group.

The other measure on which both groups performed

poorly was the percentage of information recalled on the

CFT. This score was based on Snow (cited in Lezak, 1983)

and was developed to evaluate the memory component of the

task while controlling for the quality of the original

performance on the copy trial. Both groups had difficulty

in this area suggesting a mild level of impairment.

Hypothesis 2

The second hypothesis stated that impairment ratings

based on pattern analysis of each subject's performance

75

would show no significant differences between subjects in

a drug addiction treatment program and neurological 1y im­

paired subjects. A t-test procedure was used to test the

hypothesis. There was no significant difference between

the means of the two groups (see Table 9).

76

TABLE 9

T-TEST COMPARISON OF CLINICAL IMPAIRMENT RATINGS

POLYDRUG NEUROLOGICAL (n=16) (n=15) MEAN MEAN

IMPAIRMENT RATINGS 1.81 2.33 -1.43 .163

CHAPTER V

DISCUSSION AND CONCLUSIONS

Summary

The purpose of this study was to examine the cognitive

functioning of adolescents involved in significant abuse of

multiple psychoactive drugs. The literature review re­

flected the existence of national concern regarding illegal

drug use with a major focus on the use patterns of adoles­

cents. A trend has been noted toward increased social

tolerance of the use of certain substances which have been

popularly labeled as harmless and recreational such as

marijuana and cocaine. Increased attention to the drug

problem in the United States began with an awareness of the

growing drug use by white, middle class teens. While the

popular picture of drug use 20 years ago was heroin ad­

diction in the urban ghetto and marijuana use on college

campuses, the mean age of first use by subjects in this

study was 10 years with the earliest exposure at the age of

seven.

A search for causes and effects has covered a broad

spectrum of social, personality, and medical variables.

The observation of the profound effects of intoxication

with various drugs, including the psychotic episodes

associated with amphetamine abuse, led to concern about

77

78

possible longer lasting cognitive impairment as the result

of duration or intensity of drug use. Studies which

investigated cognitive impairment as the result of involve­

ment with one drug did not support this hypothesis (Parsons

& Farr, 1981 ).

Investigation of drug taking behavior revealed a trend

toward not only involvement of younger and younger children

but also toward use of multiple substances either in se­

quence or simultaneously. The research on the cognitive

functioning of polydrug abusers with a young adult popula­

tion did find evidence of mild, diffuse brain dysfunction

(Adams et al. 1975; Grant, Adams, Carlin, Rennick, Judd, &

Schooff, 1978). Earlier research by Bruhn and Maage (1975)

on Danish prison inmates found no differences among four

subject groups: nondrug controls; users of marijuana and

hallucinogens; users of marijuana, hallucinogens, and

stimulants; and users of marijuana, hallucinogens, stim­

ulants, and opiates. Grant et al. (1976) suggest that

Bruhn and Maage's lack of identification of cognitive

dysfunction may have been the result of their analysis of

the data on a test by test basis rather than using a

clinical analysis of the pattern of individual performance

and overall impairment ratings. The most comprehensive of

the studies on young adults involved with polydrug use

(Grant, Adams, Carlin, Rennick, Judd, & Schooff, 1978)

79

found that duration and intensity of involvement with

central nervous system depressants and opiates represented

the greatest risk to the integrity of cognitive func­

tioning. These results may also explain the discrepancy

with the Danish study since depressants and opiates were

not heavily represented in that subject population.

Based on these findings, the relevant question in this

study was whether, in addition to academic and social

problems, adolescents involved in polydrug use experienced

impairment of cognitive ability. The study was a

comparison of two subject groups, adolescents with

multiple-drug use histories and adolescents with a history

of neurological trauma. Limitations on research design

included the lack of random assignment. The polydrug

adolescents were an intact group of inpatients at a private

psychiatric facility. They were being treated in an

adolescent addictive disease unit. The neurologically

impaired group was matched for age to the drug group.

These subjects had been tested using a modification of the

Halstead-Reitan battery in the three years previous to the

study. They were patients evaluated in a rehabilitation

program in the same community as the psychiatric hospital.

Their evaluation was part of a routine medical follow-up of

their injury. Fourteen of the subjects had experienced

closed head injuries most commonly related to motor vehicle

80

accidents. One of the subjects had had surgery to remove a

brain tumor. The polydrug subjects were tested with the

same neuropsychological battery. They additionally com­

pleted a medical history, sociodemographic data, and

personality assessment. The MMPI and BDI were administered

and scored by the hospital. Each hypothesis was tested

with a t-test procedure. Statistically significant results

favoring the polydrug subjects were found for 10 individual

tests. In the 23 remaining tests no differences were found

between the neurologically impaired and the polydrug

groups. On overall impairment ratings no difference was

found between the two groups.

Discussion of the Study

This study described the cognitive functioning of

adolescent polydrug abusers. It was stated that the

results of neuropsychological assessment of an adolescent

polydrug group would show no significant differences from a

group of adolescents who were neurologically impaired

therefore suggesting the existence of mild, diffuse im­

pairment related to polydrug use. The comparisons of

performance were made on each assessment procedure and on

clinical analysis of overall ability. Although the results

of the clinical analysis indicated no difference between

the groups, the explanation for the similarity between them

81

was that both groups were functioning within the lower

range of normal limits. Possible reasons for the results

are:

1. Traumatically head injured adolescents involved in

an outpatient treatment program represent a high level of

adjustment in this population and the recovery of cognitive

ability in some patients approaches normal limits with

recovery times averaging more than one year.

2. Cognitive impairment related to the extent and

intensity of drug involvement by this youthful a population

may not be reflected in neuropsychological performance.

3. Cognitive impairment from stimulant use, preferred

by these subjects, may not be reflected in performance on

the individual procedures used in this battery.

4. The mild level of cognitive impairment suggested

by the overall clinical rating of the polydrug subjects may

be descriptive of a group of adolescents who are vulnerable

to involvement in multiple-drug use.

An important question in understanding the results of

an assessment of cognitive functioning is premorbid

ability. In this study no measure of ability prior to the

onset of drug involvement or neurological trauma was

available. Measures of verbal ability which reflect old,

overlearned skills are typically felt to be the most

resistant to the debilitating effects of diffuse brain

82

damage. This resistance is demonstrated in the studies on

adult alcoholics (Parsons & Farr, 1981). Using the

Vocabulary subtest of the Wechsler scales and the oral

reading subtest of the WRAT-R as benchmarks of premorbid

ability it appears that the functioning of both groups

could be described as falling in the lower end of the

average range of ability. Grant et al. (1976) state their

opinion that it was improbable that the deficits which were

observed in their study of young adult polydrug abusers

could have reflected premorbid cognitive ability but they

had no way to control for this in their study. Related

studies on adult alcoholics have explored the possibility

of preexisting lower levels of functioning as an

explanation for the observed deficits in this population.

De Obaldia et al. (1983) studied a group of 55 men admitted

to a Veterans Administration alcohol treatment program and

found that the poorest cognitive functioning was demon­

strated by the quartile of the group reporting the most

childhood symptoms related to hyperactivity and minimal

brain dysfunction. Tarter and Alterman (1984) state.

Since the majority of deficits demonstrated in alcoholics are on tasks that involve sustained attention . . . there could be an additive effect of antecedent impairments and alcohol consumption to produce neuropsychological deficits in alcoholics, (p. 3)

Lewis and Hordan (1986) review findings which link phen-

cyclidine (POP) abusers with previous histories of learning

83

disabilities (LD) and learning disabilities with juvenile

delinquency (JD) which is frequently associated with drug

abuse. They state.

The LD-JD hypothesis derives from observation that LD is estimated to be present in 50 percent to 80 percent of the JD population, compared to estimates of LD's presence in 8 percent to 12 percent of the normal-IQ school-age population at large, (p. 192)

Despite the lack of clinical findings of cognitive impair­

ment in the current study, it is not possible to state

whether the polydrug subjects' abilities were what they

would have been in the absence of drug use.

The polydrug group was statistically superior to the

neurologically impaired group on 10 of the 33 assessment

scores, 30 tests of specific ability and three composite

intelligence scores. On only two of the tasks did the

polydrug group's performance indicate mild levels of im­

pairment when compared to clinical ratings. On the 12

items on which the neurologic group's performance suggested

impairment, seven of them were mild (within normal limits)

and five were moderate. Despite the fact that the compar­

ison of group means comes out strongly favoring the

polydrug group, the clinical assessment of each individ­

ual's performance analyzed in Hypothesis 2 showed no

difference between the groups. This finding could result

from either good performance by the neurologic group or

poor performance by the drug group. Seven subjects from

84

each group received overall impairment ratings suggesting

low average cognitive functioning (mild impairment).

Although this category falls within normal limits it is at

the lower end of this range. Three of the polydrug

subjects and six of the neurologic group showed ability

suggesting more than mild deficits. It is important to

recall that the clinical pattern analysis allows for

ratings of impairment based on relative strengths and

weakness so that an average Vocabulary score on the WAIS-R

might represent impaired functioning if is was produced by

an individual with a postgraduate degree in English. This

means that a clinical impairment rating might not con­

tribute to a lowered group mean. Although the functioning

of both groups suggests lower levels of average ability

this rating falls within normal limits and therefore it

appears more likely that the statistical similarity between

the groups is the result of the relatively good functioning

of the neurologically impaired group than significant im­

pairment of the polydrug subjects.

One explanation for the apparently intact cognitive

functioning of the polydrug group may relate to the drug

category favored by the adolescents in the study. The

drugs of choice for the adolescent group in the present

study were stimulants and marijuana with a variety of other

drugs in combination. Only two subjects listed no

85

stimulant use. This is consistent with other findings

involving this age group (Kirby & Berry, 1975). The

findings of this study are consistent with those of Grant,

Adams, Carlin, Rennick, Judd, and Schooff (1978) in

suggesting

That heavy, persistent amphetamine use is not related to neuropsychological impairment in most youthful users, although a few persons might indeed be at risk for idiosyncratic reasons (e.g., preexisting hypertension, vasculitis, or allergic diathesis) yet to be determined, (p. 1071 )

This conclusion must be cautionary because of the small

sample size and the absence of a normal group for com­

parison.

The lack of interpretable findings regarding person­

ality functioning of the adolescents in the drug treatment

program was a disappointment. Little data were available

on psychological functioning due to invalid results on six

of the MMPI's and no administration of this instrument due

to the poor reading level of two of the subjects. In a

study of the personality correlates of polydrugs abusers,

Kilpatrick et al. (1976) describe a group of 17 males, mean

age 24.59 years, as emotionally labile and overresponsive

to stimuli. They were found to be higher on measures of

state anxiety but not trait anxiety. The authors state,

Neurotocism and extraversion scores considered together and compared with Eysenck's norms (1968) categorize the polydrug users as high on both neuroticism and extraversion, which Eysenck

86

reports to be characteristic of under-socialized psychopaths, (p. 315)

Kilpatrick's group of young adults was also found to be

higher on sensation-seeking than controls. Despite

inadequate data from the MMPI, some evidence exists for

undersocialized features in the functioning of the

adolescents in the current study. Using the diagnosis of

conduct disorder under the DSM III criteria, elevation of

Psychopathic Deviance (Scale 4) on valid MMPI profiles, and

arrests as measures of social deviance, only two polydrug

subjects did not meet this criteria. The same issue,

however, can be raised with the adolescent head injured

group. Recent studies have suggested that this population

was involved in more risk-taking behavior prior to their

accidents than their peers (Lezak, 1983; Rutter, 1981).

They are described as "impulsive, overactive youngsters,

who by nature are more inclined to participate in dangerous

activities" (Begali, 1987). Responses to the BDI suggest a

moderate level of depression in the polydrug subjects.

Some of the depressive features which these adolescents

reported may have been affected by their recent hospital­

izations in addition to more chronic concerns.

Whether polydrug abuse by adolescents results in

cognitive impairment is undetermined by this study. It

does appear that polydrug abuse which emphasizes stimulant

use was not related to moderate to severe brain dysfunction

87

in the present group. Further research is needed to

resolve this question and to investigate the problem of

whether such impairment would result from drug use or if

the drug use could be subsequent to and associated with

minimal brain deficits and therefore provide a predictor of

vulnerability for drug involvement. The importance of this

question is twofold. First, if mild cognitive dysfunction

somehow, undoubtedly in combination with other variables,

contributes to involvement in drug use then prevention

strategies should focus on this population. Speaking of

this population. Grant et al (1978b) state that "It may be

necessary to educate persons with such subtle disorders

regarding their greater vulnerability to polydrug-induced

impairment (p. 183)." The second part of this issue in­

volves the special therapeutic needs of a population with

minimal brain dysfunction.

Summary of Results

The cognitive effects of polydrug abuse by adolescents

have not been studied previously and the lack of impairment

findings on individual measurement procedures in this

research cannot be taken to indicate that neurological

ability is not affected by multiple drug use. Three issues

may be especially relevant in understanding the cognitive

functioning demonstrated by the polydrug subjects of this

88

study. First, this study consisted of middle class

subjects. Stimulating home environments are highly cor­

related with the development of good verbal ability. Good

verbal skills are notoriously resistant to the effects of

mild diffuse neurological dysfunction. Second, the poly­

drug subjects of this study fit the criteria for drug

addiction according to the DSM III but within this frame­

work the duration and intensity of their drug use was quite

variable. One subject was in a third treatment program,

had extensive scars as the result of intravenous stimulant

and opiate use, began using drugs at age nine, and was on

probation for felony criminal charges related to drug use.

The opposite end of the spectrum in this group was repre­

sented by a 15-year-old with a three-year history of abuse

involving marijuana and alcohol. If the number of the

subjects in the study had been large enough, the extent and

intensity of drug use could have been compared with overall

clinical impairment ratings. The third issue, which has

been raised earlier, is the preference in this study for

use of stimulants and the lack of research support for

evidence of deficits in cognitive ability in any age group

in which stimulant use predominated.

89

Implications for Further Research

Future research in this area would need to consider

several issues which arose during this study. A larger n

would be important in increasing the power of the statis­

tical tests and to provide data for exploration of

variables related to drug use categories. Availability of

a premorbid measure of functioning such as standardized

academic achievement scores would be valuable in inter­

preting the results as would any reliable indicator of

previously established learning disability or minimal brain

dysfunction. Inclusion of a group of normal subjects would

assist in more clearly interpreting the results of the

cognitive functioning of the polydrug group.

This is an important area of study. One which in­

volves the identification of cognitive ability in polydrug

abusing adolescents. It involves the investigation of

cognitive factors as etiologic and contributory or as

effects of involvement with drug abuse. Research should

also be directed toward development of appropriate pre­

ventive and treatment interventions for adolescents with

cognitive impairment. Grant, Adams, Carlin, Rennick, Judd,

and Schooff (1978) acknowledge this need and recommend

avoiding therapies emphasizing intense emotional arousal

and insight in patients with brain dysfunction.

90

Implications for the Professional

The results of this study indicate that 10 of the

subjects in an adolescent polydrug treatment program were

identified to be functioning at or below the mildly

impaired, low average, range of cognitive ability. This

finding was based on the clinical analysis of individual

patterns of performance of each subject. Whether this

represents an effect, a cause, or a correlation to their

drug abuse it suggests that neuropsychological assessment

of this population can contribute to an understanding of

the patient's functional ability which has great meaning in

terms of effective treatment. If problems are individually

evident in attentional abilities or problem solving, ther­

apeutic interventions must respond to a need for repetition

of important material or assistance with processing treat­

ment information. Lewis and Hordan (1986) suggest that the

high recidivism rate in their population of POP abusers

could be primarily accounted for by treatment personnel's

lack of information about and accommodation of patients'

cognitive ability. In the absence of any type of im­

pairment, these are teenagers with significant adaptive

problems and for those who additionally have cognitive

deficits, identification of these and accommodation of the

treatment plan is necessary. The Lewis and Hordan (1986)

findings of impaired verbal concept formation associated

91

with POP abuse suggests that verbal therapies in which most

counselors are trained places the success or failure of the

patient on an area of relative cognitive weakness.

An additional finding is suggested by the outcome of

this study. The response bias to the MMPI questionnaire by

the polydrug subjects was disappointing. Archer (1987)

states that

For the oppositional and angry adolescent, the MMPI may present a welcomed opportunity to display noncooperation by responding in the slowest and most inappropriate fashion to each item. (p. 34)

This finding is supported by the research of Newmark and

Thibodeau (1979) on administration of the MMPI to adoles­

cents in inpatient treatment settings. Modifying the

presentation of this instrument might be useful in

obtaining valid and therefore interpretable results.

Perhaps an explanation of the validity scales and their

ability to detect a bias in responding would be sufficient

to produce an appropriate test-taking attitude. Other

options would be to tie appropriate completion of the test

to some aspect of the treatment program, to substitute

another instrument or form of personality, or to delay the

administration until the patient had developed a minimal

commitment to the treatment program. Although this would

result in the loss of data regarding initial attitudes,

information regarding the more enduring aspects of

92

personality functioning would not be lost and would be

available on more patients.

Interestingly all of the subjects approached for

inclusion in the polydrug group volunteered. Although

there was occasional manipulation when a subject agreed to

a time for the testing and at the last minute would

reschedule in favor of a basketball game, the general

attitude was cooperative. This may have been due to the

novelty of the type of testing included in this battery and

the comraderie which developed among the patients who had

completed the testing, another example of the adolescent

vulnerability to peer pressure. Nevertheless, the coopera­

tion of the polydrug subjects suggests their amenability to

this type of investigation.

Conclusions

It would be inappropriate to generalize from the

results of this study due to the small sample size and the

methodological limitations. This study does not compare

the ability of the polydrug group to a normal control of

age-matched peers. A striking finding, however, was that

the overall impairment ratings based on clinical pattern

analysis of individual performance suggested mild to severe

neurological impairment for two-thirds of the polydrug

group. The research on amphetamine use by adults has not

93

found abuse of stimulants to result in permanent cognitive

impairment. This provokes the thought that perhaps the

cognitive ability of the polydrug subjects of this study

represents a premorbid level of functioning rather than an

effect of drug use. The finding that 81.4% of these poly­

drug using adolescents have a first degree relative with a

history of alcohol or drug addiction suggests that consid­

eration of the research supporting genetic transmission of

alcohol addiction could be germaine to an understanding of

the risk factors for polydrug users. Although alcohol was

not the drug of choice for the subjects of this study it

may be that the availability and increased social accept­

ance of drug use has resulted in polydrug involvement in

teenagers who in the past would only have had access to

alcohol.

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APPENDIX A

MEDICAL HISTORY QUESTIONNAIRE

100

101

MEDICAL HISTORY QUESTIONNAIRE

Screening Items Yes No Not Sure

Difficult maternal pregnancy

Premature birth

Required postnatal observation

Hospitalized before age 6

Febrile convulsions

Learning difficulties in school

Traumatic head injury

Posttraumatic amnesia

Nontraumatic unconsciousness

Diagnostic brain tests

History of brain disease

Epilepsy

Overdose requiring hospitalization

Severe headaches

Frequent muscular weakness

Numbness of extremities

Frequent faintness or dizziness

General anesthesia

APPENDIX B

DEMOGRAPHIC QUESTIONNAIRE

102

103

DEMOGRAPHIC QUESTIONNAIRE

1. On a scale of 1 to 10 how satisfied are you with your life right now? One represents least satisfied and 10 most satisfied.

2. How would you describe your family?

a. Lower class b. Middle class c. Upper class

3. What is your parents marital status?

a. Married b. Divored c. Widowed

4. How would you describe the quality of your parents' marriage?

a. Close and warm b. Cold and distant c. Angry and hostile

5. Do you feel that you have experienced brain impairment as the result of your drug use?

6. What is your religious preference?

7. To what extent do you consider yourself religious?

a. Strongly b. Moderately c. Fairly d. Mildly e. Very Little f. Not at all

8. What was the highest grade in school completed by your mother?

9. What was the highest grade in school completed by your father?

10. At what age did you first use drugs?

11.

104

Do any of the following members of your family have history of alcohol or drug addiction?

a. Father b. Mother c. Paternal d. Paternal e. Maternal f. Maternal g. Siblings

Grandfather Grandmother Grandfather Grandmother

APPENDIX C

GLOSSARY

105

106

GLOSSARY

Amnestic - Cognitive problems dealing with recent and remote memory.

Focal - The focal effects of brain damage refer to predictable and circumscribed intellectual losses resulting from injury to a specific cite.

Impairment - The difference between a person's present level of functioning and the expected level of original ability.

Polydrug - Simultaneous or sequential use of multiple categories of drugs.

Perseveration - Meaningless repetition of a previous response prohibiting appropriate shifting of responses as task requirements change.

Premorbid - Premorbid ability is the intellectual potential or capacity which was present prior to disease, developmental anomalies, emotional disturbance, or any condition that has impaired the expression of these abi1ities.