What is stress?

Martyn Jones

Prof of Healthcare Research

School of Nursing and Midwifery, University of Dundee

Learning outcomes:

1 Distinguish between stressors, strain and stress as an interaction

2 Distinguish between major and minor life events

3 Describe how life events, coping and Type A personality may affect the course of illness

4 List and describe vulnerability and protective factors

What is stress?

• “Hardship, adversity or affliction". • “Strain" and "load" • Various models have been hypothesised to

describe the nature of stress. • Experimental investigations have tested the

adequacy of the predictions made by these models.

• Such models are known as HEURISTIC models or "discovery devices".

Models of stress

1 Engineering model.

2 Physiological Reaction Model.

3 Psychological Models

a Interactional Model.

b Transactional Model.

Stimulus Based Model.

Stress is a condition of the environment.

Stress is located in the environment.

The aversive environmental condition is the

STRESS.

The working definition of this particular model is;

"When the demand in the environment exceeds

the coping capacity of the organism"

• Noise cognitive deficits Sheldon Cohen (1980)

Cohen, Glass and Singer (1973) difficulties in discriminating between similar sounding words

• Stress (in the form of an aversive environment) can impair the development of important academic abilities.

Holmes and Rahe (1967) Social Readjustment Rating Scale (SRRS).

• average degree of readjustment

• the length of time needed for each adjustment,

• and the severity of each event.

Getting married

Which of these events has happened to you in the last 6 months? (Tick)FamilyDeath of a spouseMarriageDeath of close family memberDivorceMarital separationPregnancy or fathered a pregnancy

PersonalDeath of a close friendMajor personal injury or illnessSexual difficultiesMajor change in self conceptMajor change in use of alcoholChange in residence Major change is sleeping habitsMinor violations of the law

WorkFired from workEntered Higher EducationChanged to different line of workMajor change in responsiblity at workTrouble with boss

Rahe (1970) studied 2500 officers and enlisted men

30% of men with the highest life change scores had 90% more illness in the first month of the cruise

when compared with the 30% of the men with the lowest scores.

Problems with the model

1 How do we know which events are stressful and which are not?

2 Why don't we all react to these events in the same way? This model cannot explain individual differences.

3 It does not tell us anything about what is happening at the PHYSIOLOGICAL LEVEL.

4 It only deals with incidentals

5 Low levels of stimulation can be stressful

The response based model

• Stress in a condition of the organism. • The physiological reaction is the stress.

• It is the same for everyone when they experience stress.

• In this sense the stress reaction is non-specific.

Walter Cannon (1932) "flight or fight"

Hans Selye (late 1930"s)

• General Adaptation Syndrome.

Triphasic

1 The alarm stage

2 Resistance

3 Exhaustion.

Stage one: ALARM

Physiologic response

• Enlargement of the adrenal cortex

• Enlargement of the lymphatic system

• Increase in hormone levels, such as adrenaline leading to high physiological arousal.

Behavioural response

• Increased sensitivity to changes in stressor intensity

• Increased susceptability to illness

Stage two: RESISTANCE

Physiologic response

• Shrinkage of the adrenal cortex.

• Lymph nodes return to normal

• High hormone levels continue

• The parasympathetic branch of the autonomic nervous system attempts to

counteract the high arousal.

Behavioural response

• Sensitivity to stress is increased

• Individual attempts to endure the stressor and resist further debilitating effects.

Stage three: EXHAUSTION

Physiologic response

• Lymphatic structures become enlarged or dysfunctional or both.

• Hormone levels are further increased or maintained at high levels.

• Adaptive hormones are depleted.

Behavioural response

• Resistance to stressors (including the original one) is reduced.

• The individual often becomes depressed.

• The individual becomes physically ill and may die if the severe stress continues.

Stressor

Hypothalamus

Pituitary glandAdrenal cortex

Adrenal medulla

Sympathetic nervous system

Neural impulses activate various glands and smooth muscles

Stress hormones carried via blood stream to relevant organs and muscles

Fight or flight response

1. Corticotrophin releasing factor (CRF)

2. Adreno-corticotrophic hormone (ACTH)

1

2

SAM HPAC

The weaknesses of the model are as follows;

1 It does not account for individual differences in response.

2 It still presents the person as rather passive.

3 It cannot account for our experience of reacting or experiencing stress when anticipating an event,

Cognitive appraisal

Cognitive interpretation

Stress as an interaction

Psychological Models

a Interactional Model.

Stress as arising from the existence of problematic person-environment interactions.

Person x Environment Fit Theory (French, Caplan, Von Harrison 1982).

Two aspects of person-environment fit.

1 The degree to which an employees attitudes and abilities meet the demands of the job

2 The extent to which the job environment meets the workers needs, and in particular the extent to which the individual is permitted and encouraged to use their knowledge and skills in the job setting.

Job Demands x Job Decisions Latitude Theory (Karasek 1979)

• Demands represented in the job, and the potential control

• Low decision latitude and high demand jobs are likely to report poor health and low satisfaction.

(1)

HEALTH CARE SYSTEM

(ORGANISATIONAL FACTORS AND

WORK CLIMATE)

(2)

PERSONAL SYSTEM

(TYPE OF JOB AND WORK ROLE:

DEMOGRAPHIC AND PERSONAL

FACTORS)

(3)

WORKSTRESSORS

(4)

COPINGRESPONSES

(5)

WORK MORALE PERFORMANCE +

FUNCTION

(6)

QUALITY OF CARE AND TREATMENT

OUTCOME

Figure 1: A theoretical model of work stressors in health care and social service settings, (after Schaefer & Moos, 1993).

THE TRANSACTIONAL MODEL OF STRESS.

"When perceived demand threatens to, or does, exceed perceived coping capacity in an imagined or actual interaction with the environment".

Perceived demandPerceived coping capacity

.........................i.e. cognitive appraisal

Environmental event (actual demand)

Subsequent degree of psycho-

physiological arousal

Coping behaviour in the situation

Cognitive appraisal

Lazaurus and Folkman (1984)

primary and secondary appraisal.

Primary appraisal

potential positive, neutral or negative consequences

Secondary appraisal.

adequate resources and the ability to cope?

Reappraisal of the situation

ONGOING TRANSACTION

Cognition and Emotion

Emotions have the following components:

1 Internal bodily responses,

2 Belief or cognitive appraisal

3 Facial expression,

4 Reactions to the emotion.

The cognitive variables

1 Automatic thoughts and underlying assumptions

underlying belief systems (cognitive schema)

2 Attributions

attribute control to themselves (internally or dispositionally) or to factors in the outside world ( external or situational). Julian Rotter (1975)perceived locus of control: - internal/external

3 Predictability

4 The relationship between perceived control and perceived demand

PERCEIVED HIGH CONTROL

Ideal. Perceived as challengingExecutive stress

PERCEIVED LOW PERCEIVED HIGHDEMAND DEMAND

Stressful, Create passivity and apathy

DISTRESS HELPLESSNESS, REDUCTION IN EFFORT.

PERCEIVED LOW CONTROL

5 Self efficacy

Bandura (1989)

6 Psychosocial support

WAYS OF COPING WITH STRESS

1 Deal with the environment

2 Deal with the way the person interprets the event

3 Deal with the way the person behaves,

4 Dealing with the underlying physiology.

The Architecture of Coping

1 A person realises they are having difficulty in coping with demands and threats to their well-being.

2 Coping in a particular situation is important to person, and having difficulty depresses the person.

Primary appraisal

(DEMAND APPRAISAL)

Secondary appraisal

(RESOURCE APPRAISAL)

Coping has been defined as:

“Constantly changing cognitive and behavioural efforts to manage external and/or internal demands that are appraised as taxing or exceeding the resources of the person”

Lazarus and Folkman (1984).

There are three stages of coping;Primary Appraisal

Secondary AppraisalCoping

Figure: Stress Appraisal of situations

Potentialstressor

Primary AppraisalDemand Appraisal

Secondary AppraisalResource Appraisal

Perception of Stress

Positive ConsequencesLittle or no harm

Adequate ResourcesAbility to cope is good

Not a threat Threat reduced

[1] Kaplan, Sallis and Patterson (1993) Health and Human Behaviour. McGraw-Hill, New York, p123.

Cognitive restructuring Reframe the demands present , and the resources available to cope.

Problem solving Activities directed to change the stressful nature of the situation .

Tension reduction Activities designed to reduce psycho-physiological arousal

Use of social skills Use of negotiation, communication and humour.

Self-disclosure/catharisis The sharing of, and expression of current emotional state.

Structuring The assemby and organisation of coping resources

Seeking information Gaining information about likely sources of stress in the environment to reduce perceived threat.

Stress monitoring General awareness of tension, negative thoughts, and personal arousal levels.

Assertive responses Non-aggressive statement of needs and wants.

Avoidance/withdrawal Escape by removal of self from situation.

Suppression/denial Carry on as if nothing has happened, or ignore the stressor.

Self-medication Use of medication, alcohol etc to reduce arousal

Coping resources include;

Social support Friends, colleagues, family who are available.

Beliefs and values Personal philosophy and belief systems.

Wellness Overall health.

Self-esteem Personal beliefs in own self worth.

Theoretical approaches to coping:

1 The psychoanalytic perspective on coping

2 Coping as a personal trait or style

3 Coping as a sequence of changes

4 Coping as specific methods or focii

1 The psychoanalytic perspective

• Various forms of adjustment. • Realistic thoughts and actions which confront

the person

Problems with such an approach;

i Contact with reality is seen as an essential precursor of effective coping.

ii Defines coping in terms of success.

2 Coping as a personal trait or style• Reliable and stable personality traits or styles

• Those showing certain predispositions are more able to cope with stress and suffer fewer unpleasant consequences

• preferred coping styles in ambiguous situations.

• A number of preferred coping styles have been described in recent years

i Repression-sensitization

Repressors have lower reaction times to emotional words, than perceptually vigilant individuals who have faster times to emotional rather than neutral words.

Avoidant vs vigilant/approach

These measures have differentiated between;

1 Low Anxious individuals

2 True repressors.

3 Sensitisers

Socially desirable response tendencies.

Problems with this approach ;

1 There is little evidence.

2 Personal traits/styles are poor predictors of situational appraisals and coping behaviours .

3 Assumes that coping is unidimensional and does not change across time.

Monitor-blunter dimensions.

Information processing.

3 Coping as a sequence of changes

Kubler Ross (1969)

denial

anger

bargaining

depression

acceptance.

4 Coping as specific methods or fociiBillings and Moos (1981)

1 Active-cognitive coping

2 Active-behavioural coping

3 Avoidance

Lazarus and Folkman (1984, 1985, 1986)

1 Problem focused coping, which targets the problem facing the individual

2 Emotion focused coping, which targets the emotional response of the person to the situation which is threatening to exceed resources.

Coping

Problem focused Emotion focused

Behavioural Cognitive Behavioural Cognitive

Attempts at control and problem solving

Situational redefinition and restructuring

Seeking social support, information

seeking

Emotional expression

AvoidanceEscape

Passive coping

Wishful thinkingDistancing

DisplacementDistractionInformation avoidance

Emotional inhibitionRepression

Denial

Figure: The architecture of coping

How may life events and personality affect the course of disease?

How does this relate to patients?

Coping with a diagnosis

Shontz (1975)

• Shock

• Encounter Reaction

• Retreat

Background factors

•Demographic and social factors

•Physical, social and environmental factors

•Illness related factors

The crisis of illness

Cognitive appraisal

Is my illness serious?

Adaptive tasks

•Illness specific

•General tasks

Coping skills

•Appraisal focused

•Problem focused

•Emotion focused

Outcome

Figure: Coping with the crisis of illness

Adaptive tasks

Illness-related tasks• Dealing with pain and other symptoms• Dealing with hospital environment and treatment

procedures• Developing and maintaining relationships with health

professionals

General tasks• Preserving an emotional balance• Preserving self-image, competence and mastery• Sustaining relationships with family and friends• Preparing for an uncertain future

Coping skills

Appraisal focused• Logical analysis and

mental preparation• Cognitive redefinition• Cognitive avoidance or

denial

Emotion focused• Affective regulation• Emotional discharge• Resigned acceptance

Problem focused• Seeking information and support• Taking problem solving action• Identifying rewards

How does stress affect health?

Ogden (2001)

suggests that there are two pathways by which stress may affect health via;

1 Physiological changes:Sympathetic Adrenal Medullary system (SAM)

Hypothalamic-Pituitary-Adrenal-Cortical system (HPAC).

2 Behavioural changes:

Stressor

Hypothalamus

Pituitary glandAdrenal cortex

Adrenal medulla

Sympathetic nervous system

Neural impulses activate various glands and smooth muscles

Stress hormones carried via blood stream to relevant organs and muscles

Fight or flight response

Immune function and stress

• Both SAM and HPAC have an impact on immunological functioning

• Most cells with immunological function are generally found in the broad class of leukocytes, or “white cells”.

• Lymphocytes make up some 20% of circulating leukocytes and are of two types, B and T cells.

Cell-mediated immunity

a Killer T cells which attack foreign material

b Helper T cells which receive reports of invasion

c Suppressor T cells which reduce cell mediated and antibody mediated immunity processes as the infection is overcome.

d Memory T cells which remember previous infections.

e Delayed hypersensitivity T cells

Antibody-mediated immunity

Lymphocytes called B cells are involved here.

B cells produce plasma cells which produce antibodies (protein molecules called immunoglobulins).

This process may be facilitated or inhibited by suppressor T cells.

Non-specific immunityThe third arm of the immune system are the phagocytes (non-specific immunity) which respond to any kind of antigen (i.e. those at the cellular or humoral level).

Psychoneuroimmunology

• Relationship between psychosocial processes and the activities of the nervous, endocrine and immune systems (Sarafino 1990).

• The brain seems to operate as a control centre to balance immune function, ensuring adequate defences to protect against opportunistic infection.

• Prevents over activity in the form of autoimmune diseases (rheumatoid arthritis, multiple sclerosis, AIDS).

• Stress related emotions of anxiety and depression may have a large impact on the immunological functioning of a person.

Keicolt-Glaser et al (1984) • 75 medical students one month before a

series of final exams, on the morning of the first examination.

• Natural killer T cell activity was lower in the second sample.

• Those showing high number of stressful life events had significantly lower levels of killer T cell activity.

Schleifer et al (1983) • T and B cell levels and responses to (Con A) and

(PHA)

• 15 men whose wives had died from metastatic breast cancer.

• 6 week intervals during their wife’s illness, at 2 months after the wife’s death and a number of times in up to 14 months post-bereavement.

• Lymphocyte function was diminished post bereavement, reductions in immune function were apparent from one month following the death of spouse.

• Immune function recovered to pre-bereavement levels in the measures following 2 month post-bereavement assay.

2 Behavioural responses to stress

Ogden 2001

effects of stress on specific health related behaviours and on behavioural change in general.

Smoking

The initiation of smoking has been linked to stress levels in adolescents

(Wills 1985, see Ogden 1996)(Santi et al 1991).

(Carey et al 1993, see Ogden 1996)

Perkins et al (1992, see Ogden 1996)

(Gilbert and Speilberger 1987, see Ogden 1996).

Alcohol• Tension reduction theory suggests that people drink

to reduce tension• People are more likely to drink when depressed or

anxious (Violante 1983, see Ogden 2001).

General Behaviour change• People experiencing high levels of stress are more

likely to perform behaviours which increase their chance of becoming ill or injured.

Individual differences

• Beliefs and physiological changes

Beliefs may have a direct effect on physiology

• Internal, stable, global attributional style

Kamen and Seligman (1987)

• Pessimism

Reduction in T cells and immunosuppression

Cognitive evaluation of life eventsOatley (1988), schemata, depressogenic attributional

style• internal/external

(lack of personal ability), • stable/unstable)

(my lack of control results from a cause that is long standing),

• global/specific (I cannot control all parts of my life)

Learned Helplessness Theory Seligman (1984)Social cognition model of the link between stress and

psychiatric morbidity.

Type A behaviour pattern• A syndrome characterised by competition, hostility and

exaggerated commitment to work (Rozanski et al., 1999).

– Standardised Semi- structured interview (Jenkins Activity Survey)

– Framington Type A Scale (Haynes et al, 1978)

• A large cohort study showed an independent effect of type A behaviour on CHD incidence (Rosenman et al., 1975) later studies were not able to replicate similar results (Case et al., 1985) (Shekelle et al., 1985) or reported contradictory findings (Ragland & Brand, 1988)

• The relationship between Type A and health outcomes is weak, using established assessment

Type A behaviour pattern• Hostility is a broad psychological construct, encompassing

negative orientations towards interpersonal relationships and includes such traits as anger, cynicism and mistrust (Rozanski et al., 1999)

• Issue of stress reactivity, with hostile individuals showing higher heart rate, blood pressure and blood platelet activity

• Behaviour patterns

– Health Behaviours

– Temperament

– Parenting

– Coping at work

Psychosocial Modifiers of Stress

A number of factors may moderate the relationship between stress and illness.

1 Exercise:

2 Gender:

3 Coping style:

4 Life events:

5 Social support

6 Personal control

7 Hardiness

There are four types of Social support:

i Esteem support

ii Informational support

iii Social companionship

iv Instrumental support

Does social support affect well-being?

Schwarzer et al (1994)

Relation between stress and health is not automatic.

It is moderated/mediated by factors such as coping style, perceived control and social support

Main effect model

Distress

Stress

Social support

Buffer model

Distress

Stress

Social support