Psychology: Stress

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The body's response to stress

People use the term stress to mean different things. 3 most common ways of defining stress:

  • stress as a reponse to something in the environment
  • stress as a stimulus (stressor) in the environment
  • stress as a lack of fit between perceived demands and perceived ability to cope with those demands

2 main ways our body responds to stress: both involve adrenal gland:

  • we have 2 adrenal glands, lying just above the kidneys
  • each adrenal gland made up of two distinct sections
  • 1) the adrenal cortex
  • 2) the adrenal medulla

Sections release different sets of hormones into the bloodstream and are controlled by two different pathways:

  • pituitary adrenal system
  • sympathomedullary pathway
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Pituitary-adrenal system

  • Involves the adrenal cortex
  • is under the control of the hypothalamus and pituitary gland
  • hypothalamus: small structure at the base of the brain
  • 1) when higher brain centres evaluate a stressful situation: instruct hypothalamus to release CRF (corticotropin releasing factor)
  • 2) CRF travels to pituitary gland
  • 3) Pituitary gland releases number of hormones into the bloodstream which control many vital body functions
  • ACTH travels to the adrenal cortex and stimulates the release of hormones called corticosteroids into the bloodstream
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Sympathomedullary pathway

  • Control of adrenal medulla is different
  • Autonomic nervous system (ANS) is a network of nerve pathways running from centres in lower parts of the brain
  • goes out to the organs of the body such as heart, digestive system, blood system and various glands including adrenal medulla
  • ANS centres in brainstream = controlled by higher brain structures esp. hypothalamus
  • Role of ANS is to maintain normal functioning of bodily systems in response to demands
  • ANS has 2 subdivisions - sympathetic + parasympathetic
  • each division has pathways running to internal organs of the body
  • when sympathetic subdivision activated: see patern of bodily arousal
  • Heart rate and blood pressure increase
  • fats and carbohydrates are mobilised, activity in digestive tract slows down
  • when parasympathetic subdivision is activated: see opposite effect, heart and blood pressure return to normal and digestion speeds up
  • this is a pattern of calm and bodily relaxation
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Sympathomedullary pathway cont

  • adrenal medulla is controlled by the ANS
  • activation of the sympathetic branch stiumlates it to release adrenaline and nonadrenaline into bloodstream
  • adrenaline - well known arousal hormone
  • adrenaline and nonadrenaline reinforce the pattern of sympathetic activation 
  • heart rate and blood pressure are stimulated along with further mobilizing energy reserves
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Activating the body's stress response

  • When aroused, the 2 systems prepare the body for energy expenditure
  • Corticosteroids, adrenaline and nonadrenaline mobilize energy reserves and sustain blood flow and heart rate to get oxygen to muscles 
  • do this under normal circumstances to supply daily needs
  • in stressful situations, have to consider the role of higher brain centres
  • hypothalamus and ANS function perfectly well without involvment of higher brain centres
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The General Adaptation Syndrome

Stage 1:

  • Alarm: presence of a stressful event (stressor) is registered
  • Hypothalamic-pituitary system secretes surge of ACTH which releases corticosteroids from adrenal cortex
  • sympathetic ANS activation leads to increased adrenaline and nonadrenaline being secreted from adrenal medulla
  • body is now prepared to respond to perceived threat through fight or flight

Stage 2: 

  • Resistance: the body's stress response is fully activated and apparently coping with the stressor and things seem under control from the outside

Stage 3:

  • Exhaustion: occurs when the stressor is long lasting or chronic
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Stress-related illness and the immune system

Last phase of Selye's GAS is the exhaustion stage:

The view that when exhaustion occurred led to a stress-realted illness has changed and it's beleived hormones themselves are responseible for the negative effects of stressful situations

2 main reasons for this change in view:

  • hormone supplies are rarely exhausted
  • We know more about the widespread effects of hormones on the body 
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The immune system

  • Immune system is our main defence against infection by foreign agents
  • immensely complicated network of cells and chemicals throughout the body that functions to seek out and destroy invading particles
  • any agent that stimulates an immune response = antigen
  • familiar antiens: bacteria, viruses, fungi
  • sometimes particles that are normally harmless cause an overreaction of the immune system
  • this is the basis of allergies
  • key featurse of imune system are white blood cells
  • WBCs are produced in the bone marrow and circulate in the blood stream
  • 2 types of white blood cells: lymphocytes and phagocytes
  • Non-specific immunity: phagoycytes are cells that surround and ingest foreign particles wherever they encounter them
  • Cell based immunity: Lymphocytes are called T cells and seek out and destroy and cells recognised as foreign
  • Antibody based immunity: B cells, destroy invading agents while they are still in the bloodstream and before they enter the body's tissues
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Effects of stress on the immune system

Infection and diseases: stress can cause psychological changes that weaken our immune system. As a result, health can be negatively affected and infections and illness occur more frequently and recovery takes longer

Indirect effects:  stress causes release of ACTH from pituitary gland in brain, signals  the adrenal glands to release anti-inflammatory hormones which inhibit immune cell functioning

Psoriasis and eczema: symptoms of inflammatory skin disorders such as psoriasis and eczema worsen with stress. Stress interferes with the immune system's ability to deal with the inflammation assosiated with these disorders 

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Short term stressors and the immune system

  • Has become well established in recent decades that psychological stress can affect many aspects of immune function
  • even brief periods of stress e.g school or college exams can result in significant suppression of immune system functioning
  • effects include a decline in ability of white blood cells to perfrom their functions in fighting antigens
  • stress can slow down wound healing
  • immune system plays important part in healing wounds by preparing tissue for repair by cytokines
  • transient stressors e.g examinations alter the production of cytokines and slow down this process
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Chronic stress and the immune system

  • Chronic long lasting stressors have been found to have consequences for immune-system functioning
  • Conflict in interpersonal relationships: couples whose interactions are hostile and negative show less adaptive immunological responses after these interactions
  • Death of a spouse: death of a close relative such as a wife, child or parent is assosiated with immune system dysfunction
  • Care giving: another form of chronic stressor assosiated with immune system dysfunction is care giving, in particular caring for a spouse with dementia. Caregivers frequently isolated and experience overwhelming demands on their resources both physically and psychologically 
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Age and gender differences in the effects of stres

Telephone survey of over 1000 American adults found that:

  • Women significantly more likely to report problems and being stressed than men (84% - 76%)
  • People under the age of 65 more likely to be stressed than older people (82% - 70%)
  • Kiecot-Glaser et al (2003) suggest there are significant differences between how men and women react to marital conflict
  • show that women have more adverse hormone and immunological changes
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Stress in everyday life: Life changes and daily ha

Stressors can be classified into 2 broad categories:

  • Discrete (one off)
  • Continuous 

Most research on discrete stressors focuses on study of major life events such as divorce or job loss that require significant degree of adjustment

Continuous stressors such as ongoing life problems permeate our daily reality

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Life changes: The Social Readjustment Rating Scale

  • Major way of measuring relationship between life changes and wellbeing is Social Readjustment Rating Scale
  • Scale was developed by Holmes and Rahe in 1967
  • SRRS has been the most widely used of all methods for assessing life stress
  • the more we have to adjust to an event, the more stressful the event is
  • Holmes and Rahe made list of major life events based on their experience as clinicians
  • asked men and women of various ages and backgrounds to rate the events in terms of amount of readjustment they would require
  • death of a spouse came top and given arbitrary value of 100
  • Once scale was construcuted, was a matter of asking participants to check off any of the 43 life events they had experienced over a given period
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Evaluation of the life changes approach

  • Many studies carried out on the link between life events and health breakdown using the SRRS
  • although significant correlations are often found, tend to be relatively small suggesting a relationship between stress and health but not a strong one
  • Becomes clear that there are problems with the scale
  • Individual differences: scale's values for different events are arbitrary and will vary from person to person 
  • Causality: relationship between SRRS score and health is correlation so tells us nothing about causality 
  • Positive life events: some life events are positive. People getting married probably see it as a positive chaneg
  • Self-report: self-report of life events can be surprisingly unreliable
  • Dated and androcentric:  the approach is now rather dated nd androcentric, more recent studies have used developments of this scla ethat focus more on contemporary issues that effect both males and females
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Daily hassles

Daily hassles: minor events that arise in the course of a normal day. Include, for example, concerns about work such as disagreements with a colleague or being late for the bus. Some of these might be fairly routine and some might be more unexpected (e.g a malfunctioning computer) 

Research suggests that adverse effects of daily hassles can be offset by the corresponding experience of dailyuplifts which are positive everyday experiences

Why are daily hassles so stressful? :

  • Minor daily stressors affect wellbeing by accumlating over a series of days to create persistent irritations, frustrations and overloads that result in more serious stress reactions such as anxiety and depression
  • Altnernative explanation is that daily hassles arise from pre-existing chronic stressors and therefore amplify effects of that existing stressor
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Evaluation of research into daily hassles

Causality: what does the research tell us? most data on daily hassles is correlational meaning we can't draw causal conclusions about relationship between daily hassles and stress related problems

Cultural differences: social support is an important protective factor against stress and there are clear cultural variations in how it is used. Researchers have looked at the way different ethnic groups use social support as a protection against stressors including daily hassles

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Workplace stress

Sources of stress in the workplace:

  • Sources of stress depend on the type of work/enterprise you are looking at
  • Physical environment: space, temperature, lighting and arrangement of an office can all affect the individual
  • Physical stressors make work more difficult and more energy has to be expended to overcome them
  • Work overload: seem to moving towards a culture in which long hours of work are seen as a mark of esteem, to the cost of both the individual and social structures, such as the family
  • Lack of control: in many organisations, other people often determine work load and work patterns
  • Role ambiguity: occurs when requirements for a particular work role are unclear or poorly defined, this is a major facttor in work-related strss
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Research on workplace stress

Many studies have been carried out on stress in the workplace e.g Marmot et al (1991) carried out 3 year longitudinal study of over 3000 Whitehall civil servants

They found that people with low job control were 4x more likely to die of a heart attack than those with high job control

Job control and illness were negatively correlated: as job control decreased, chances of stress related illness increased

Finding was supported by review of research which concluded that a combination of high job demands and low job control is associated with an increased chance of heart disease

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Evaluation of research on workplace stressors

Extraneous vvariables: despite the apparent link between lack of job control and stress-related illness in many studies, possible that important variables e.g personality were not controlled for

Job control: having high levels of job control can be stressful for some people

Individual differences: as other cultures take on the working practices of the West, similar relationship between lack of control and stress related illness becomes evident however not all workers with low job control and high demand jobs become ill

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Personality factors and stress: Type A behaviour

Early 60s: Friedman and Rosenman (1974) studied behaviour of patients suffering from coronary heart disease and proposed a particular behaviour pattern was associated with increased vulnerability to this stress related illness

Pattern is known as Type A behaviour. Characterized by: constant time pressure (being in a hurry), doing several tasks at once, being intensely competitive at work and other social situations, easily frustrated by the efforts of others

Recent research on Type A behaviour:

  • Williams et al (2003) reported on a 15 year study focused on younger people who had Type A personality
  • found that certain aspects of Type A behaviour were unhealthier than others, hostility and impatience put individuals at increased high blood pressure. This is a major precursor to heart attacks, strokes and other symptoms of cardiovascular disease
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Explaining the relationship between Type A behavio

Several mechanisms have been proposed to explain the link between Type A behaviour and an increased risk of CHD

Compared to Type Bs, Type A individuals respond more quickly and strongly to stressful situations in terms of behaviour and physiological responses

Evaluation of type A behaviour:

Lack of consistent research support: Since original work by Friedman and Rosenman, many studies have looked at relationship between Type A behaviour and CHD. Significant correlations have been found, but these are nevery very high and negative findings have been reported

Role of hostility: Type A behaviour pattern has been more closely analysed, turns out a critical personality variable is hostility

Type A behaviour and hardiness: Many Type A individuals survive quite happily with their pressured and competitive lives  

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Personality factors and stress: The "hardy persona

According to Kobasa, concept of hardiness is central to understanding why some people are vulnerable to stress and some resistant. Hardiness includes a range of personality factors that defend against the negative effects of stress. These are:

Control: the belief you can influence what happens in your life rather than attributing control to outside influences

Commitment: sense of purpose and involvement in the world around you, including people as well as jobs and careers

Challenge: life changes are seen as challenges to be overcome or as opportunities rather than threats and stressors

Kobasa et al rated participants rated participants on the presence or absence of the three factors: hardiness, social support, regular exercise

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Evaluation of hardiness and hardy personality

Participants: much of Kobasa's work has been carried out with white male workers, hard to generalise to other groups

Components of personality: control, commitment and challenge have never been clearly defined. Control may be an important part of commitment and challenge rather than being separate to them

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Methods of stress management

Methods of managing stress can be divided into 2 major categories:

Physiological approaches: drugs and biofeedback used to target stress response systems directly

Psychological approaches: using cognitive and behavioural tranining to help people control specific stressors in their lives, use of relaxtion and increasing hardiness to reduce bodily arousal in association with stress

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Physiological methods of stress management: Drugs

Most likely drugs to combat stress: benzodiazephines, beta-blockers

BZs:

  • Librium and valium 2 examples
  • most prescribed drugs for psychological disorders, can be effective against states of stress and anxiety
  • work by reducing brain arousal
  • BZs enhance actions of natural brain chemical: GABA
  • GABA tells neurons that it contacts to slow down/stop firing
  • GABA receptors react with BZs on outside of receiving neuron
  • Opens channel that allows Cl- ions to make neuron less responsive pass to inside of neuron
  • BZs bind to special sites situated on GABA receptor, boosting actions of GABA, allows more chloride ions to enter neuron therefore more resistant to excitation
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Beta-blockers

  • Do not enter the brain
  • directly reduce activity in sympathetic nervous sytem around the body
  • beta blockers can be effective against symptoms such as raised heart rate and blood pressure
  • work by reducing activity of adrenaline and nonadrenaline
  • adrenaline and nonadrelanine are key agents in sympathetic arousal
  • beta blocker drug binds to beta-adrenergic receptors and blocks receptor from being stimulated
  • by blocking sympathetic arousal, beta blockers slow heartbeat, lessen force with which heart contracts and reduces blood vessel contraction
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Advantages and disadvantages of drugs

Advantages:

Speed and effectiveness: can work quickly and rapidly reducing dangerous symptoms such as raised blood pressure

Research support: meta analysis of studies on treatment of social anxiety showed BZs were more affective than other drugs such as antidepressants

Availability: drugs can be prescribed immediately

Weaknesses:

Dependency: long term use, especially of BZs, can lead to psychological and physical dependency. People coming off BZs will experience physical withdrawal syndrome with symptoms such as increased anxiety, tremors, headaches

Side effects: All drugs have side effects, BZs can cause drowsiness and affect memory

Only target symptoms: Drugs treat symptoms, not causes

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Physiological methods of stress management: biofee

Biofeedback technique involves recording activity of physiological systems of the body's stress response such as heart rate, blood presure or tension in neck muslces

People encouraged to try various strategies to reduce physiological readings. These strategies include relaxation, meditation or altering posture

Evaluation of biofeedback:

Effectiveness: Biofeedback can be successful for some individuals especially children who enjoy technological aspects in controlling

Role of relaxation: often found to be no more effective than muscle relaxation procedures, suggests feedback on systems such as blood pressure not a vital part of the procedure

Expense: expensive in terms of equipment and time

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Cognitive Behavioural Therapy (CBT)

Stress Innoculation Training

  • Cognitive behavioural method designed to prepare individuals for future stressors and to promote resiliance
  • People are taught a range of coping strategies they might use to deal with stress
  • Followed by exposure to series of graduated challenges to they can practise these coping skills
  • SIT has 3 phases
  • Conceptualization: Main cognitive element. Client encouraged to relive stressful situations and analyse features. What was stressful? How did they cope? Discussions can be individual or in groups. Clients reach more realistic understanding of demands being made on them
  • Skills traning and practice: once elements of stressful situations have been identified, clients can be taught specific and non-specific strategies for coping with them
  • Real life applciation- final stage is for client to go out into the real world and put the training to the test 
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Evaluation of SIT

Targeting symptoms and causes: Meichenbaum's programme is directed at both ends of the stress problem (sources of stress and coping strategies) by reviewing copying methods used in past, clients gain clear understanding of their strenghts and weaknesses

Effectiveness: combination of cognitive theory and behavioural therapy makes stress innoculation training a powerful method of stress management

Practicality: takes time, application and money

Difficulties: evidence that we cope with life's stressors can reflect basic aspects of our personality, possibly innate or acquired during early experience 

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Progressive muscle relaxation

Effective muscle relaxation has to be learned. Progressive muscle relaxation is an active approach to reducing bodily arousal

Standard procedure: train clients to consciously clench and unclench muscles and get them used to sensations of tension and relaxation 

Eventually, client understands sensations well enough to use progressive muscle relaxation in every day life as a method to reduce bodily arousal

During relaxation, stress response mechanisms are inactive, heart rate and blood pressure fall and parasympathetic subdivision of nervous system is activated

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Evaluation of progressive muscle relaxation

Effectiveness: if practised regularly, relaxation techniques are effective in reducing stresss but are not practical in all situations due to space and time constraints

Practicality: these techniques take time and space, if you are stuck in a particular situation it may not be possible


Targeting symptoms: relaxation techniques address bodily or psychological arousal by reducing activation of stress-response systems 

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Hardiness training

Kobasa's belief that hardiness is an important element in stress management led her to propose ways it could be increased. Procedure has 3 aspects, first 2 are similar to the first stage of stress inoculation training:

Focusing: clients are encouraged to spot signs of stress such as muscle tension, increases in heart rate and anxiety

Relieving stressful encounters: clients analyse recent stressful situations in terms of how they were actually resolved and ways in which they could have turned out better and ways they could have turned out worse

Self improvement: central to hardiness is the belief that you can cope with life's challenges

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Evaluation of hardiness training

Theoretical issues: concept of hardiness itself has been criticised. Relative importance of the 3 factors: control, commitment, challenge, is unclear

Generalisability: Kobasa's studies usually involve white, middle class businessmen, results can't be generalised to women o r to different classes and cultures

Effectiveness and practicality: few systematic studies of effectiveness of hardiness training, requires commitment and motivation

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