Stress Studies

Kiecolt-Glaser et al: Whether the stress of ST stressors had an effect on the immune system of medical students. Blood samples were taken one month before the exam period (low stress) and during the exam period (high stress). Immune system functioning was measured by NK activity in the blood samples. Participants were also asked to complete a questionnaire to measure other life stressors. NK activity was significantly reduced in the second blood sample. Therefore suggesting that stress decreases immune system functioning.

Marucha et al: Exam related immune changes have shown to have a dramatic effect on the length of time it takes for a wound to heal. Inflicted a punch biopsy in the mouth of students during the summer holidays or 3 days before an exam. Wounds given before the exam took 40% longer to heal compared  to wounds given during holidays

Segerstrom and Miller: Conducted a meta analysis of 293 studis conducted over the past 30 years. They found that short term acute stressors can boost the immune system, prompting it to ready itself for infections or other challenges. Long term chronic stressors led to supression of the immune system. Finally, the longer the stress, the more the immune system shifted from potentially adaptive changes to potentially detrimental changes.

Lazarus: Stress and illness is not a simple relationship. Health is affected by many factors, such as lifestyle and genetic factors, therefore there may be little variance left that can be accounted for by stress. Health is fairly stable and slow to change, difficult to demonstrate that exposure to a particular stressor changes health. To demonstrate how stress affects long term would require continuos measurements over a long period of time, this would be expensive and impractical.

Holmes and Rahe: Developed the social readjustment rating scale (SRRS), based on 43 life events taken from their analysis of over 5000 patient records. They used 400 participants to establish the stressfullness of each event. They were asked to provide a numerical number for the readjustment required from a particular event. Scores were totalled and averaged to produce the life changing unit (LCU).

Rahe et al: Number of life events experienced was positively correlated with illness. SRRS used on three US navy  ships (2700 men). They were also asked to fill in a questionnaire, noting all…