MRCPsych seminar series

Epidemiology of addictive disorders: a brief review

Dr Stuart McLaren

March 2010

consumption/use

dependence

problems/harms

Epidemiology of substance use

Sources of data

• Drug seizures

• Persons dealt with for drug offences

• Drug-related crime

• Prescription audit

Sources of data

• ONS General Household Survey

-smoking

-alcohol

Surveys of psychiatric disorders

Deaths• British Crime Survey –illicit drugs• Crime and Justice Survey• National drug treatment database (NDTMS)

Prevalence of psychiatric disorders /1000 adult population

Neurotic disorders All 164

Psychosis M 5

F 6

Alcohol dependence M 119

F 29

Drug dependence All 37

2000 ONS

Lifetime prevalence of drug use

• Overall 35.5%• Cannabis 30%• Amphetamines 12%• Cocaine 7.7%• Ecstasy 7.3%• Opiates <1%

-heroin 0.7%-methadone 0.4% 2006/2007 BCS

Prevalence rates of problem drug users in England 2005/06 per 1000 population aged 15 to 64

Rate 95% CITotal 9.97 9.74-10.40Opiates 8.60 8.46-8.99Crack 5.93 5.73-6.25Injecting 3.90 3.78-4.11

Hay et al. 2007

Prevalence rate of problem drug users in England per 1000

population aged 15 to 64 by gender

Rate 95% CI

Male 15.32 14.86-15.87

Female 4.64 4.61-4.99

Hay et al. 2007

Prevalence rate of problem drug users in England per 1000

population aged 15 to 64 by age

Rate 95% CI

15-24 years 10.07 9.85-10.66

25-34 years 21.43 20.76-22.24

35-64 years 6.10 5.96-6.39

Hay et al. 2007

Drug use in last year

• General population (16-59 years)

10% taken illicit drug

3% used class A drug• Prison populations

73% used illicit drugs

50% heroin/cocaine2006/2007 BCS & 2003 HO

Prevalence of drug dependence

All 3.7%

Cases per 1000 population• Cannabis only 25• Ecstasy 6• Amphetamines 4• Cocaine 2• Opiates/cocaine 1

2000 ONS

Injecting –England & Wales

• Whole population (age 11-44 years)

-ever injected 4/1000

-regular injector 2/1000

-past month 1/1000

2000 ONS

Main drug in adult treatment populations (n=174250)

Heroin 66%

Crack 6%

Cocaine 6%

Methadone 8%

Cannabis 7% NDTMS 2007/8

Main drug in treatment population under 18 (n=14725)

• Cannabis 78%

• Heroin 5%

• Crack 1%

• Cocaine 5%

Individual clients receiving specific treatment modalities 2007/8

England 198, 254Inpatient 6,742 (3%)Specialist prescribing 99,963 (50%)GP prescribing 47,036Day programmes 20,537Residential rehab 4,306

2007/08 NDTMS

Illicit drug trends

• Drug dependence has doubled over the last decade (now c. 4.2%)

• Increasing multiple drug use• Opiate use stable, male mortality increasing• Use of opiates correlates with deprivation• Stimulant use has increased• Cannabis use may be falling• Use shows no class gradient

Comorbidity-70% of opiate users have another current psychiatric disorder

Anxiety disorder 28%Affective disorder 26%Antisocial personality disorder 18%Schizophrenia 7%

ECA, Regier, 1990

Substance related harms and risks

‘with drugs nothing is always. Their use does not carry a guarantee of danger, but neither is their safety guaranteed.What one needs to ask about any substance is not whether in absolute terms it is safe, but rather the degree of risk which may attach to its use.’

Harms of drug use:

• Physical health, including death

• Mental health

• Social circumstances

• Educational & employment status

• Criminal justice status

• Safety & welfare of others, including children

Factors in drug harms

• Contaminants

• Route

-BBVs

-accidental overdose

-smoking and lung damage

-drinking and gut cancers

• Addiction or dependence

Harm to others

• Transmission of blood-borne viruses

• Violence

• Driving

• Family disruption

• Damage to children

• Community dislocation

Drug-related deaths 1997-2002

• Tobacco (UK, approx.) 500,000

• Alcohol (approx.) 25,000-200,000

• Opiates 6,194

• Cocaine 508

• Amphetamines 436

• Solvents (UK) 361

• Ecstasy 200

Problem drug users - all cause mortality

• X 12 (SMR 1244, 95% CI 876-1678) time higher than in general population aged 15-54 years [DORIS cohort, 2008]

• In cohort studies 1-2 % die every year

Demographics of drug-related deaths

• Mostly male (74%)

• Most under 45 years (71%)

• Causes – accidental poisoning (64%), intentional self-poisoning (13%)

• Opioids +/- other drugs (69%)

(np-SAD 2009)

UK AIDS cases- total to 2005

total %• Gay sex 12721 59• M/F sex 5877 27• IDU 1227 6• M. to I. 594 3• Blood 871 4• Other 262 2

HPA

UK HIV infections

total %

• Gay sex 34265 -

• M/F sex 27864 -

• IDU 4273 6

• Blood 1798 -

• Other 4615 -HPA

Hepatitis C infection

• General population 0.5%

• Chronic infection 0.4%

• Prison populations 7%

• IDUs 30-80%

Hepatitis C transmission –England 1992-2002

• IDU 91%• Blood transfusion 2.5• Blood products 2.3• Sexual exposure 1.8• Renal failure 0.9• Other 0.8• Vertical 0.6

HPA

Epidemiology of drinking and alcohol-related harm

consumption/use

dependence

problems/harms

Epidemiology of substance use

Consumption and risk – units/week

Men Women

Low risk <21 <14

Hazardous 22-50 15-35

drinking

Harmful drinking >50 >35

Alcohol consumption

Weekly alcohol consumption above recommended limits

M 28%

F 17%

F aged 16-24 years 33%

[doubled since 1992]

2002 GHS

Hazardous drinking

AUDIT score 8 or more:

• Overall 25%

• M 38%

• F 15%

2000 ONS

Prevalence of alcohol dependence

SADQ – rate per 1000 population (7% dependent, 1% severely dependent)

All M F

• Mild 69 111 28

• Moderate 4 7 1

• Severe 1 1 02000 ONS

Prevalence of alcohol dependence

• Peaks at 20-24 years

• M 24%

• F 7%

2000 ONS

Comorbidity – 37% of those with alcohol disorder have another mental disorder

Anxiety disorder 19%Antisocial personality disorder 14%Affective disorder 13%Schizophrenia 4%

ECA, Regier, 1990

Alcohol trends

• CAGE scores increasing between generations of men

• Dependence and hazardous drinking peak in middle occupations

• Heavy drinking shows no clear class gradient

• Younger people and women at particular risk

Smoking prevalence

16 years and above: M. 27%

F. 25%

16-19 years: F. 29%

M. 22%

11-15 years 9% (2006)2002 GHS

Young people

Aged 11-15 ~10,000 sample

Regular smoking F 10% M 7%

Alcohol last week 23% F=M

5.3u/week in 1990

10.4u/week in 2000

Drugs last year 18%