The SAM stress pathway (sympathomedullary pathway)
the hypothalamus sends nerve impulses along the sympathetic ANS fibres. This causes organs to respond in certain ways. The pupils dilate, salivary gland inhibits, heart beats faster, the brochi inhibit, intestines inhibit and the liver stimulates glucogenesis and the bladder relaxes. Also the adrenal medulla secretes adrenaline and noradrenaline.
The HPA stress pathway (pituitary-adrenal system)
The hypothalamus secretes CRF, pituitary gland secretes ACTH, adrenal cortex secretes corticosteroids and the liver stimulates glucogenesis.
Gerra et al
Found lower immune activity in those individuals who were recently bereaved compared to a matched control group. This difference was observed 40 days after the event and in some cases after 6 months.
Cohen et al
394 p's completed a questionaire on the number of stressful life events thy had experienced in the past year and their answers were collated into a stress index score. P's were then exposed to a low dose of the common cold. 82% of p's became infected with the virus. The more stressed a person had been the more likely they were to get ill.
Evaluation of Cohen et al
- High ecological validity - field study, took place in the p's natural settings so we can relate the findings to real life.
- use of questionaire - the gain of information is retrospective, recall relies on accurate memories, likely to have faults in memories so the validity if the results is reduced. also the use of questionaires leads to demand characteristics, p's may lie on the questionaire in order to appear more socially desireable.
- correlation research - cause and effect cannot be established and we can only say there is a relationship between stressful ife events and developing viral infections.
- the dependent variable isn't specific enough - stress index doesn't tell us exactly which stressful life event has the effect on the immune system.
Kiecolt-Glaser et al
Volunteer sample of 75 first year medical students. Blood samples were taken 1 month before final exams and the day of their first exams. The number of T cells and killer cells were measured. P's also filled in a questionaire on other stressful life events. They found the levels of killer cells and T cells fell between the two samples suggestng stress lowered the activity of the immune system. They found especially weak immune systems in those who had recorded a large number of stressful life events in the questionaire.
Evaluation of Kiecolt-Glaser et al
- natural experiment - natural form of stress rather than an artificial one (eg sleep deprivation) Stress was natural so results have more external validity.
- No control over extraneous variables - Other variables could also affect the immune system for example medical disorders which means there is a lower number of T cells and killer cells anyway.
- Correlational research - cause and effect cannot be established and we can only say there is a relationship between stress and immune activity.
- Biased sample - results aren't representative
- Scientific method - makes results more valid
Segerstrom and Miller
Meta-review of 294 studies which looked at the effect of stress on the immune system. found stress lowers immune system. this can be used as evidence of reliability for Cohen et al and Kiecolt-glaser et al.
Outline the Social Readjustment Rating Scale (SRRS
- Developed by Holmes and Rahe
- Scale to assess life stress
- Consists of many stressful life events which each have an LCU score depending on how how stressful the event is.
- eg. death of a spouse - 100LCU points, change of school - 20 LCU points
- total of all stressful events in the last year, higher score = more stressed
- score of 150+ 30% more likely to have stress related illness
- score of 300+ 50% more likely to have stress related illness
Evaluation of the Social readjustment rating scale
- 10-30% of people haven't experienced any of the life events on the scale.
- Doesn't take into account that some of the life events are positive eg. marriage
- the scale is considered dated - one of the life events is 'wife going to work' this no longer causes the same amount of stress as it used to as this is now the norm however the scale still suggests this is very stressful. Therefore the scale is no longer relevant to today's society
- the scale doesn't account for individual differences - eg. Christmas, some people love it whilst some people hate it.
- Score on the SRRS and health problems are correlational, so cause and effect cannot be established
Rahe et al
2500 male american sailors completed the SRRS. They then went on a 6 month tour of duty. their health problems were monitored throughout the tour and it was found that there was a positive correlation between the scores on the SRRS and illness.
Evaluation of Rahe et al
- large sample - anomalies can be eliminated
- Biased sample - only american soldiers, results can't be generalised
- SRRS may have been completed incorrectly making data invalid and consequent conclusions also invalid
- correlational - cause and effect cannot be established, only say there is a relationship between LCU score and illness. having said this, seeing a correlation within such a large sample is rare and shows the strength of this research
- Doesn't take into account stress that occurs after the SRRS is completed. this is especially important considering a tour of duty will be very stressful
- Natural form of stress - higher ecological validity
- no control over extraneous variables - eg illness is easily spread on a boat, hence illness may not be due to stress
Outline the Daily Hassles scale
- Developed by Lazarus
- a daily hassle is a minor event that arises during the day which causes small amounts of stress eg losing keys
- a daily uplift is a positive event which counteracts the effect of daily hassles, eg getting a compliment
- both daily hassles and uplifts are usually shortlived but can accumulate and hence intensify over time
- original scale had 117 items
- different variations for subgroups eg. students or old people
Bouteyre et al
1st year psychology students completed daily hassles/uplifts scale alongside a depression scale. there was a postive correlation between the hassles score and depression, a symptom of stress
Evaluation of Bouteyre et al
- Biased sample - results not representative
- correlational research - no cause and effect established
- dependent on the accuracy of completion of the daily hassles scle and the depression scale.
- validity dependent on accuracy of depression scale as well as the hassles scale - results likely to be invalid
Gervais et al
A group of nurses were asked to keep diaries for a month recording all the daily hassles and uplifts they experienced. Gervais found that hassles decreased job perfromance (a sign of stress) whereas uplifts improved job performance
Evaluation of Gervais et al
- Use of diary to collect data - retrospective gain of data, relies on accurate recall which is unlikely to be 100% correct. Also the use of the diary may lead to demad characteristics where p's lie in the diary in order to appear more socially desireable. Also it is likely that due to being busy, the nurses may forget to complete the diary and then make up data in order to fill it in for the researcher. All this leads to invalid data and hence invalid conclusions to the research.
- Biased sample - unrepresentative results
- Natural form of stress - higher ecological validity
- Correlational research - cause and effect cannot be established
Evaluation of the Daily hassles scale
- supporting research - Bouteyre et al and Gervais et al
- Weaknesses of supporting research - see evaluation of Bouteyre and Gervais
- Comparisons to the SRRS - Daily hassles takes into account positives and negatives where as SRRS only looks at negatives. 10-30% don't experience life events on the SRRS, everyone experiences daily hassles
- Has a real world application - seen with the Gervais study. Can analyse data and distinguish what causes poor job performance and correct these things in order to improve working conditions
- use of sub-groups - more relevant to each part of the population so conclusions are more valid
Johansson et al
P's worked in a swedish saw mill. High risk group of p's - 14 finishers who had the most stressful job in the mill which was skilled, machine paced and the pay of the whole factory was dependent on their productivity. Low risk group of p's - 10 cleaners, who's work was less stressful and slower paced. urine samples were taken to measure adrenaline and noradrenaline (stress hormones). found the high risk group had more stress hormones and more stress related illness.
Evaluation of Johansson et al.
- Natural experiment - natural form of stress, natural environment, higher ecological validity
- Scientific measure - produces valid results which aren't susceptible to bias.
- Biased sample - only relevant to saw mill workers and so results can't be generalised
- small sample size - anomalies cannot be seen and hence eliminated
- correlational research - cause and effect cannot be established
Marmot et al
10308 civil servants had their job control assessed at the beginning of the study and again three years later. Job control was assessed on two ways:
1) self report questionaire completed by each p's
2) report by the p's personnel manager
Records of illness and absence were then kept over the three years. It was found there was a correlation between a lack of job control and illness.
Evaluation of Marmot et al
- Large sample - eliminates anomalies
- Biased sample - only aged 35 -55, results aren't representative
- longitudinal study - not just predictions of the researchers, their ideas were checked and proven 3yrs after the start of the research. Increases reliability of the results
- self-report questionaire - retrospective gain of data relies on accurate recall and hence leads to invalid results
- assessment by personnel manager - subject to bias leads to invalid results
Outline a hardy personality
Control - see themselves as being in control of their own decisions and life
Commitment - hardy people are involved in the world around them and have a sense of purpose
Challenge - see problems as things to overcome rather than stressors
Features of an A type personality
- easily angered
- high achievers
- report more stress and health problems
Features of a B type personality
- angry less
- not competitive
- worry less
- sensitive to other's feelings
- no ambition
Forgays et al
looked at two groups of mother (A type and B type)
A type personalities found motherhood more stressful than B type personalitites
Friedman and Rosenman
A volunteer sample of nearly 3200 healthy Californian men aged 39-59 were assesed over 8.5 years. personality type was assessed by interviewing them and recording their answers and their behaviour during the interview. they were classified as either A or B type.
part 2 of the study was the follow up eight years later when incidence of coronary heart disease was recorded. 257 p's got CHD, 69% of these were A type personalities
Enhance the natural brain chemical GABA which tells the neurones it contacts to slow down and hence has a quietening effect on the brain.
Reduce the activity of adrenaline and noradrenaline and they act on the body reducing symptoms of stress such has high blood pressure and an increased heart rate.
Advantages of drugs as a method of stress manageme
- Speed and effectiveness - rapidly reduces symptoms
- Research support - Hidalgo et al found that BZs were more effective than other drugs
- Availability - can be prescribed immediately and the range of treatment is increasing
Weaknesses of drugs as a method of stress manageme
- Dependency - addiction and withdrawal symptoms when patient tries to stop using them
- Tolerance - need more and more drugs to feel the effects of the drugs
- Side effects - BZ's cause drowsiness and effect memory. BBs narrow airways.
- only target symptoms - don't treat causes and only mask the problem.
- NICE (national intstute of clinical excellence) report - recommended BBs shouldn't be used for high blood pressure because other drugs are more effective. BBs increase chance of getting type 2 diabetes
3 stages of stress inoculation training (SIT)
1) conceptualisation - reliving stressful experiences and identifying what was actually stressful
2) Skills and training - clients taught strategies and relaxation techniques to prevent the client becoming stressed
3) Real-life application - client goes out into the real world and puts training into practise. Contact with the therapist is maintained
Evaluation of Stress Inoculation Training
- Targets symptoms AND causes - doesn't just mask the problem whereas drugs only treat symptoms
- No side effects - where as drugs can cause other illness
- Practicality - takes a lot of time, money and effort on the behalf of the patient
- little evidence to support the strategy
- changing cognitions and behaviour will always be difficult and there are arguments to suggest that disorders such as stress are biological and can therefore not be fixed by such treatment.