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  • Created on: 21-02-18 18:35

Physiology of Stress- General Adaptation Syndrome

GAS- Selye
1. ALARM REACTION- 'fight or flight response' to stressors. Hypothalamus triggers adrenal medulla to release adrenaline and noradrenaline

2. RESISTANCE TO STRESS- if stressor continues body recovers and copes & adapts but resources e.g hormones are being used

3. EXHAUSTION- body can't maintain functioning. Initial symptoms= sweating, raised heart rate. Finally stress related illness e.g cardiovascular problems

+ Research, Selye. Rats given injections, surgery and excerise and found response to stress was same as humas (aches, loss of apetite) suggests one stress response.
- Unethical to inflict pain on rats & can't generalise to humans

- Doesn't recognise individual differences e.g age, gender - 'tend and befriend' response

- Reductionist, simplifies complex human behaviours down & suggest seperate stages

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SAM & HPA Pathways

Sympathomedullary Pathway (SAM) ACUTE STRESS
1. Hypothalamus detects stressors in environment e.g lion
2. The Sympathetic branch of Autonomic nervous system activated.
3. Stimulates adrenal medulla to release adrenaline and noradrenaline- 'Fight or Flight'

Hypothalamic Pituitary System (HPA) CHRONIC STRESS
1. Hypothalamus detectes stressor in environment 
2. Releases CRF
3. CRF travels to pituitary gland 'master gland' which secretes ACTH
4. This travels to adrenal cortex which releases cortisol into bloodstream 

+ People with adrenal glands removed have to have hormone supplements, suggesting importance of pathway in responding to stress

- Individual differences. Taylor 'tend and befriend' response. Women nurturing behaviours (oxytocin)

- Animal based research. Can't generalise to humans, as complex behaviours

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Role of Cortisol

Cortisol permits steady supply of blood sugar, so source of energy

+ effects- tolerate more pain, deal with stress

- effects- cardiovascular problems e.g dysfuntion of heart & blood vessels.
impaired ability of immune system

+ Research Newcomer.  ppts given cortisol levels high enough to produce levels as high as chronic stress events. Not as good at recalling passages compared to less cortisol. Suggests cortiosol affects cognitivr ability (memory)

+ Cushings syndrome. Prolonged activation of HPA (lots of cortisol) leads to weight gain and memory lapses

+ Objective, scientific measures. e.g can measure levels of cortisol

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Stress related illness- Immunosuppression

Immune system- defends against disease.

Antigen- bacteria/ virus/ funghi 

White blood cell- fights against antigens

Immunosuppression- the impaired ability  of the immune system to fight illness

Stress increase likelihood of illness, not cause.

+ Kiecolt Glaser. Natural experiment. 75 medical students. Using blood samples to measure Natural Killer (NK) cell activity. & questionnaire life events, loneliness. Found month before exams higher NK cell, than during exams. & immune systems were weakest in lonely ppts. Suggests chronic stress causes immunnosupression

+ Kiecolt Glaser. 13 women volunteers caring for relatives with senile dementia. Gave biopsy (small wound) and those caring for took 9 days longer, and appeared to be more stressed on stress scale.

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Immunosupression Evaluation

+ Research support for immunnosupression. Kiecolt Glaser. 
- Biopsy experiment did not control extraneous variables e.g marriage status (providing comfort to women) or habits e,g smoking (reducing stress but could have already caused poor immune system)

- Most research is correlational as unethical to induce stress, so no cause and effect. Longitudinal studies may be better as immune system functioning changes over time.

+ Practical applications. Health practitioners can identify stress related illness and give appropriate therapies

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Cardiovascular Disorders

Cardiovascular disorder (CVD)= prolonged stress causes problems to the heart and blood vessels e.g hardened arteries , high blood pressure and coronary heart disease (CHD)- clogged artieries with fatty material.

Can be directly caused e.g activation of bodily stress systems e.g SAM & HPA pathway.
Adrenaline and noradrenaline cause increased heart rate so has to work harder.

or indirectly by stress causing unhealthy lifestyles e.g smoking, drinking
______________________________________________________________________________________+ Research. Williams. 13,000 people 10 question anger scale & found highest scores 2 1/2 times more likely to have had a heart attack. 256 had heart attacks. SNS linked to CVD.

+ Research. Cobb and Rose found air traffic controllers had higher blood pressure (hypertension) than other workers, suggesting more stress linked to CVD.

- Correlational research as unethical to induce stress. No cause and effect. 

- Extraneous variables not controlled e.g smoking, drinking (indirect effects), unhealthy behaviours may have caused

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Life Changes Source of Stress

Social Readjustment Rating Scale
Measures stressful life events linked to stress-related disorders.
43 major life events on a scale. Highest death of spouse and lowest minor violation of the law. 

+ Research Rahe. 2,200 male sailors assessed on SRRS and records kept of health. Found positive correlation (+0.118) between life changes and illness over 6 month tour.
- correlational as unethical to test stress. Cannot establish cause and effect. Depression may be caused by other factors.
- androcentric, all male, females may respond to stress in different ways

+ Retrospective studies. Recalling from past less reliable

- Cumulative effect of daily hassles may be better explanation as life event changes are rare.

- Self report measure. Social desireability bias to be presented in best possible light

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Sources of Stress- daily hassles

daily hassle= everyday irritation causing elevated stress e.g being stuck in traffic
accumulation effect= minor hassles build up creating persistent irritations, stress builds up
amplification effect= chronic stress 'wears people out' making more prone to stress

Measuring Daily Hassles:
Kanner et al
Hassles Scale- Self report measure of 117 negative items e.g losing things
Uplifts Scale- 135 positive items - daily uplifts e.g hearing good news

+ Research support. Kanner. 100, 45-64 years old ppts completed Hassles and Uplifts Scale (HSUP). Did it for 9 months & life events scale 6 months. Found hassles better predictor of well-being than life events and uplifts. Negative correlation: frequency hassles & well-being
- self report  measure. Retrospective, less reliable

- Cross-cultural differences. Collectivist cultures more social support, so less stress.

+ Practical applications, helping form coping strategies for stress, therapy

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Workplace Stress

Workplace stressors= aspects of the work environment which have a negative impact on health e.g work overload, deadlines (direct) or smoking, drinking (indirect).

Workload= amount of work being given and expected to complete by employers
Control= level of control over work load and patterns

+ Research. Johansson. Natural experiment looking at 14 'finishers'- repetitive, isolated jobs
and 10 cleaners- sociable, self-paced work. Took urine samples & measured adrenaline and noradrenaline. Found high risk 'finishers' more stress hormones on work days than 'high risk' cleaners. Also had higher levels of stress related illness.
- lack of control e.g time of day samples

+ Research. Marmot. 10,000 civil servants. higher grade (accountants) and lower grade (administrative) less work control. Found high work load not linked to CHD. Low job control and low grade workers, high CHD. 3x more likely to have heart attacks. So high job control desireable.
- Correlational. Lack of cause and effect.

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Workplace Stress Evaluation

+ Research. Johansson and Marmot. 

- Not all workplace stressors harmful. Stress can increase self-esteem, confidence. 

- Workplace is changing so research no longer relevant e.g people working from home.

+ Practical applications. Letting people in charge of their own hours and pace and work reducing stress-related illness. 

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Physiological measures- Skin Conductance Response

Skin Conductance Response= a way of measuring electrical conductivity within the skin as an indication of psychological and physiological arousal

Immediate stress activates the sympathetic branch of the Autonomic Nervous System (ANS). Adrenaline causes sweating, increased heart rate and blood pressure.

Sweat increases skin conductivity so polygraph (lie detector) using electrodes on fingers to measure current. They have to sit quietly for 30 mins so unstressed before. 

+ Research. Villarejo. Ppts completed tasks different levels of stress e.g maths questions and stressful stimuli. Found readings able to detect different stress levels. 76.5% success rate. 

+ Research. Khalfa. Different types of music played to arouse emotions of fear, happiness... SCR found readings greatest for fear and happiness. suggesting effective. 

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SCR Evaluation

+ Research. Villejero- different levels of stressful tasks. found more stressful higher readings. 76.5% success rate
- Laboratory experiment, highly controlled, lacks ecological validity.

+ Research. Khalfa.- different types of music simulating emotions. Fear and happiness strongest suggesting effective.

- SCR affected by external factors e.g weather and internal factors e.g effects of alcohol. Extraneous variables

- Not reliable measure for lying. Psychopaths have been found able to lie without any physiological effects suggesting reveal little

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Individual Differences- Personality

Personality= traits that give an individual their unique characteristics

Type A= time urgent (multi-tasking) , competitiveness (aggressive) & hostility (irritated)
Linked to hypertension (increased blood pressure) and CVD

Type B= non-competitive, relaxed, lower stress levels
Good health

+ Research. Friedman and Seligman. Longitudinal study of 8 1/2 years of 3200 men. Structured interviews about everyday pressures & done in provocative manner e.g very slowly so Type As interrupt. Found 257 CHD and 70% Type A. So vulnerbale to CVD
- androcentric, male based, can't generalise.
- lifestyle variables may have affected e.g smoking, drinking

- Type A is too broad. More useful to look at specific personality traits e.g hostility, particularly useful.

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Type C Personality

Type C:

  • Supression of negative emotions
  • Consistent
  • Introverted
  • Unassertive
  • Prone to illness due to stress, particularly cancer

+ Research. Morris. 75 women visiting cancer clinic interviewed about expressing emotions. Found women with cancerous breast lumps were less angry than women with less cancerous breast lumps. Supports link between cancer and supression of emotions. 
- unethicsl. Psychological harm as the topic of cancer is sensitive
- practical applications. Helping Type C express emotions to keep healthy.

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Hardiness Personality

Kobasa- Type D:

3 key features:

  • Commitment- self purpose
  • Control- personal control over what they're doing
  • Challenge- see change as normal and challenges to be mastered

+ Research. Kobasa. 800 male business executives used SRRS. Found HIGH stress and LOW illness had hardy personality. HIGH stress and HIGH illness did not. Suggests hardy experience stress, do not get ill.
- androcentric, male based, cannot generalise

- Most research uses self-report measures, social desireability bias so positive light

- Labelling is too specific (A,B,C & hardy) individuals may have many characteristics/ may lie to fit a certain group

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Biological Method Stress Management

BZs- reduce nervous system functioning e.g xanax
Treat anxiety
Slow down central nervous system by enhancing GABA which binds to GABA receptor. Has a quietening effect by increasing chloride ions creating a channel to flow. 

+ Easy and cost effective
+ Research. Davidson. Found 78% patients with anxiety disorder improved compared to 20% of placebo. 
- Addiction and only short-term (weeks) otherwise side-effects e.g drowsiness

Beta-Blockers- reduce sympathetic nervous system of ANS activity rather than brain.
Block nerve impulses reducing symptoms e.g increased heart rate. Bind to receptor on heart so not stimulated.
+ Research. Beversdorf. Found ppts asked to speak publically & do maths task while being videod. Stressed ppts with BB performed as well as non-stressed

- Side effects e.g nightmares, hallucinations but no addiction

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Stress Inoculation Therapy

Stress Inoculation Therapy is a form of psychological treatment and CBT- so changes way person thinks

Phase 1- Conceptualisation
Client attempts to understand sources of stress (behavioural, psychological, emotional

Phase 2- Skills acquisition
client is taught specific & non-specific coping strategies to practise. e.g learning to relax through breathing, muscle relaxation.
Then using Imagery to imagine how they would deal with a situation

Phase 3- Application 
Apply skills to real life. Role play and then real-world

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SIT Evaluation

+ Research. Holcomb. 26 psychiatric patients with depression and anxiety. a) SIT b) SIT and drug treatment or c) drug treatment. Found SIT more effective and those doing SIT had fewer admissions in the next 3 years. SIT superior.
- unethical, may have caused psychological harm to test patients

+ SIT deals with causes not symptoms, long term treatment

- Time consuming (8-15 sessions over a year) and requires highly motivated patients as they have to attend to therapy. 

- Overly complex. It may be that only one part of training is required for treatment. 

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Biofeedback= partly biological treatment and partly psychological treatment.

Deals with physiological response to stress. Arousal of sympathetic nervous system of ANS. They learn voluntary control over involuntary control.

1) RELAXATION- techniques to relax reducing activity and no adrenaline produced

2) FEEDBACK- connected to machines to show activity. increases/decreases. Asked to do relaxation techniques while looking at machines
e.g EEG, electrical activity of brain
SCR, sweat activity

3) OPERANT CONDITIONING-  reward experienced when reduced activity, so increased lieklihood of behaviour repeated

4) TRANSFER- learn to transfer skills to real world

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Biofeedback Evaluation

+ Research. Lemaire. Biofeedback to 40 medical doctors ( stressful job) 3x a day for 28 days. Found stress levels decreased significantly but not in control group.
- Lacks population validity. All medical students, cannot generalise

- Expensive and time consuming, 1 month +

- Treats symptoms not the cause of the problem

+ No side effects like drugs. Non-invasive

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Gender Differences

'tend and befriend'
females respond to a threat through protection of offspring (tend) and seeking social support (befriend)

Women produce more oxytocin causing nurturing and co-operation. Also have more investment in children (giving birth to them) so need to protect. An adaptive response

Problem focused coping= strategies to eliminate stressful situations e.g taking control, taking responsibility, evaluating pros/ cons... MEN

Emotional focused coping= strategies to eliminate emotional distress e.g venting emotions, denial, seeking social support... WOMEN

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Gender Differences Evaluation

+ Research. Matud. 2,816 people assessed coping strategies. Found women rated stressful life events as more negative than men. Women more family and health related issues, men more financial related issues. Women cope worse as negative emotional focus.
- retrospective recall

- Often based self-report measures. So social desireability bias and retrospective recall

- Simplistic to divide way people stress into male/ female. More complex reasons

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Role of Social Support

Social support= the degree of assistance and resources available from others to cope with stress

buffer hypothesis- the more social support, the better one is able to cope with stressors, as it acts as a buffer

Types of social support:
Esteem support- an individual percieves other to value them, allowing them to feel compotent to deal with stress

Emotional support- an individual percieves others care for them and understand their situation, giving them support

Instrumental support- indirectly e.g helping them to have more time. directly- helping with the actual problem

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Social Support Evaluation

+ Research. Orth-Gomer et al. Found 776 male Swedish 50 year olds most common factor for CVD was smoking or lack of social support. Those with no support 5x more likely to die than supported. suggests link between social support and good health.
- lacks population validity. Androcentric- all male, so can't generalise.

- Differences in amount males and females benefit from social support. Generally males use instrumental and females emotional support

- Social support not always beneficial. Can have negative effects e.g enocurgament to do drugs

- Methodoligcal problems. Hard to test different types, so can't tell which is most effective.

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