Outline and evaluate research into effects of stress and immune system

Prolonged exposure to stress is claimed to weaken the immune system. Research has been done in this area to prove this. Kiecolt-Glaser et al conducted a study with 75 volunteer medical students. Stress levels were assessed by blood samples taken from the students one month before they were due to sit their final exams, this was the low stress condition, and again at the end of the fist day of their final exams, this was the high stress condition. They analysed the number of T-cells present in both blood samples, these attack foreign bodies in the tissue of the body. In addition to this, participants also had to complete a questionnaire which assessed loneliness, mental difficulties and life events.

It was found that the levels of T-cells were higher in the sample taken a month before the final exams in comparison to the sample take at the end of the first day of final exams. Also, level of T-cells were lower for the participants who were experiencing stressful life events, and where also lower for participants who felt most lonely. From this, it can be concluded that the hormones produced as part of the stress reaction reduce the number of T-cells produced by the body. This, in turn, reduces immune functioning. This study also supports that prolonged exposure to stress weakens the immune system.

This study is a natural experiment. This is a strength of the study as it had high ecological validity because the stressful situation which was examined was real and natural occurring. This makes it easy for the findings to be generalised to other settings. However, a weakness of this study was the sampling procedures. The participants in this study were volunteers, for this reason it is hard to generalise the results. The students that…