To what extent does research support a link between stress and the immune system?

There has been extensive research into the link between stress and the immune system that shows that the link is indeed very strong with a positive correlation. The research is seen in the general adaptation syndrome, Stone's experiment on stressful events and the links to symptoms, Cohen et al experiment on the common cold, and Keicolt Glaser who looked into immune function. Stress has been found to suppress the immune system allowing people to contract …

…immune response is not evenly distributed in blood so could easily be missed when a sample was taken. In conclusion to the experiments it is seen that stress is almost a definite cause of a suppressed immune system although it may not be the only reason that the immune system is suppressed. As it is not entirely sure whether stress causes the suppression of the immune system or the suppressed immune system leads to stress.