Rahe, Mahan and Arthur http://www.youtube.com/watch?v=uoHTlYabQE8

Today… This morning This afternoon Aims and context of Rahe et al study This afternoon Procedures of Rahe et al study Timed essay on Rahe procedures(if time)

Questions What effect can stress have on our body? Can stress make you ill? What did Selye find about stress?

Context Psychosomatic: Relationship between stress and illness A link between psychological state and physical health Relationship between stress and illness Immune system Cardiovascular system (heart and blood)

Context Thinking back to PY1, what did Selye find in his research in his research on rats? Stress and illness Holmes and Hawkins Not poverty itself which causes TB, but the emotional effects of poverty

Context Hawkins (1957) Compared TB patients to controls. Matched for age, race etc. Increase in “disturbing occurrences” in the TB patients. Is there a link between stressful events and illness?

Context Issues with methodology Research may lack…? There are biases inherent in using hospital samples and drawing conclusions from retrospective studies ... few attempts have been made to put the life stress and subsequent illness hypotheses in non hospital populations. Dr Richard Rahe

Context Another issue Social Readjustment Rating Scale (SRRS) All previous studies measure stress in different ways. Social Readjustment Rating Scale (SRRS) 43 critical life events based on 5000 case studies All about life changes, both positive and negative Life change units (LCU) calculated by asking 400 people to rate them in terms of stress

Context Could we expose individuals to certain stressors, and measure their rate of illness? If not, why? Retrospective studies: issues Recall from past Investigator effects Sample bias

Aims To overcome the methodological issues of retrospective studies by carrying out a prospective study with more control. A normal population would be used (sailors) Investigate the relationship between stressful life events and future illness.

Procedures Read the procedure on pg 81 Fill in the blank information on the sheet

Findings What was the relationship between Total Life Change Units (TLCU) and illness? What was the correlation co-efficient for the TCLUs six months before the cruise and illness while on board? Relationship stronger for cruiser 1 and 3, and for married men

Findings Decile groups All participants ranked in terms of their TCLUs and put into one of ten bands, each containing 10% of the total.

Findings Decile groups show a general trend, but it was an uneven distribution. Groups banded into “High” and “low” illness Plot this data into a bar chart How clear is the relationship now? Look at scatter graph on pg 82. Summarise these results

Findings and conclusions More findings Read pg 91. What last piece of evidence is there? Conclusions What is the main conclusion? Read through the rest of the conclusions and highlight

Evaluating the methodology Pg 84 has some good evaluation points. Using the pointers on the handout, evaluate the study One evaluation point each, pass on.

Alternative Evidence Rubin et al (1972) Predictive relationship between SRE scores and later illness in naval aviators in vietnam In other words, the higher the stress score, the more likely they were to be ill. What did Vidal (2006) and Gupta and Gupta (2004) Find?

Alternative Evidence Major life changes vs minor daily stress What minor stresses (hassles) can you think of? See daily hassles sheet DeLongis et al (1988) +.59 correlation between daily hassles and next day illness Two interpretations of this...

Alternative Evidence Rahe found a link between stress and illness Descriptive rather than explanatory Kiecolt-Glaser et al (1984). Blood tests taken before and during the exam period. Levels of natural killer cells significantly lower during the exam period. Suggests that short term predictable stressors reduce immune system functioning increasing illness.

Alternative Evidence Which piece of alterative evidence for Langer and Rodin could be used here? Could stress be good? Evans et al (1994) sIgA levels increase for very short term stress Use three colours to highlight research that supports, contradicts, or develops Rahe’s research (some may be more than one colour).