Outline and Evaluate research into the effect of stress and the immune system

Research into the effect of stress on the immune system has shown that chronic and acute stress can have different effects on health and well being. Kiecolt-Glaser was one of the main researchers involving stress and the immune system, and she conducted an experiment on medical students to see what effects take place. This was measured in NK (Natural Killer) cell activity one month before exams and during the exam period. It was discovered that during exams, which was the more stressful period students had a decrease in NK activity. increased vulnerability to illness. This study showed high levels of ecological validity, as the experiment was not artificial, and was supported by Arnetz, who found decreased leucocyte activity during times of unemployment in Sweden. Hoever, there have been studies that have decreased the reliability of the above studies. For example, Fischer found an increase in leucocyte activity during the splashdown of the astronauts in the Apollo, showing that stress may increase the immune response. Furthermore, Arnetz's study could lack validity in other countries, as people may react differently to those in Sweden.Studies into ongoing or chronic stress also have had conflicting results. One of the main types of ongoing stress is that of marital relationships. Kiecolt-Glaser carried out a study and found that those who had separated from their husbands in less that a year showed less signs of healing from blisters. Furthermore, Malarkey tested new relationships, and asked 90 couples over a 24 hour period to solve possible conflicts such as those of finance. Malarkey found that marital conflicts produced significant changes in the production of adrenaline and noradrenaline, meaning that this could lead onto poorer immune functioning. However, this cannot be generalised, due to individual differences. Women have been found to react differently to different stressful situations than men, as they have different hormones in their bodies (K-G). Furthermore, there has been other research created to show that this relationship between stress and the immune system could be more curvilinear. Evans found both increased levels of sIgA when students were asked to talk infront of others and also decreased levels over the exam periods. He proposed that the immune system has an up-regulation and a down-regulation system. Lazarus also pointed out that there are more factors that could cause an increased or decreased immune response, not just stress. These factors could be to do with genetics or lifestyle. Furthermore, health is considered fairly stable, and therefore it is difficult to demonstrate how exposure to stressors can have health related problems. In conclusion, there is no doubt that stress can influence the immune system, but more research is needed to show whether other factors influence this, as well as determining the specific relationship to whether stress decreases or increases the immune response.