Outline and Evaluate research into the relationship between the immunes system and stress-related illness.
Stress has been widely identified to be linked with illness, which has therefore attracted researchers to investigate the relationship between the immune system and stress. Cohen et al for instance conducted a study where 369 participants were asked to complete a questionnaire which measured their Psychological Stress Index, consisting of a scale measuring their own perception of their stress levels, stressful life events in the previous years and negative emotions. The P’s were then given a nasal spray containing a respiratory virus and placed in quarantine, in order to test whether they would develop a cold. The results found that 82% of P’s developed a cold, but more importantly that people with high stress levels in the PSI were more susceptible to developing the clinical cold. In effect what Cohen concluded from this data is that stressful experiences and emotions can cause immunosuppression.
Similarly Kiecolt-Glaser carried out an experiment measuring the effects of chronic stress on the functioning of the immune system. During the experiment the levels of natural killers cells ( a type of lymphocytes) of 75 medical students were recorded, using a blood sample, one month before and exam and once again during the exam. In order to measure their stress levels, Ps were asked to complete a questionnaire containing questions concerning negative life events and feeling of social isolation. The findings showed how the levels of NK cells dropped dramatically during the exam, particularly for Ps who reported feelings of isolation. The correlation between high stress levels and a deficiency in NK cells led the experimenters to conclude that stress can reduce immune function, making people temporarily more vulnerable to illness.
In contrast to Cohen’s experiment, Kiecolt-Glaser’s was a natural experiment whereby Ps were tested using a naturally occurring...
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