Full Title: Consider whether research supports the view that stress is linked to illness.

Research has shown that there may be a link between stress and illnesses, such as cardiovascular disorders and a negative effect on the immune system. However some research has also suggested that stress can have a positive effect on the immune system.

Krantz et al. (1991) conducted an experiment to investigate the extent to which mental stress causes myocardial ischemia (decreased blood flow to the heart) 39 cardio-vascular patients and 12 control subjects were asked to perform three mental tasks. An arithmetic task, a Stroop task and a public speaking exercise. Each of these tasks was designed to create mild stress. Blood pressure readings were taken, and the extent to which blood vessels around the heart contracted was measured. This study found that CV patients who displayed the most myocardial ischemia also had the highest blood pressure during the tasks. The control patients showed least myocardial ischemia and blood pressure rise. Also, an intermediate group of subjects who either had mild myocardial ischemia, or none at all, when performing the tasks, also only experienced a moderate increase in blood pressure.

From this study we can conclude that stress does indeed have a direct link between performing a stressful cognitive task and activity which could damage the CV system. However, there are several criticisms of this study. The fact that not all CV patients responded in the same way suggests that individual differences play an important role. Also, there are ethical issues about putting patients who suffer from CV disorders under stressful conditions, in order to see if their condition worsens. However, patients did consent to participating in the experiment, and were not put under extremely stressful conditions. No worse than they should experience during a normal working week. Another criticism of this study is that no control group was used to compare CV patients when stressed and unstressed. Patients may have shown signs of myocardial ischemia and increased blood pressure when completely relaxed. If this is so, then the studies conclusions are unjustified and the whole study is invalid.

There are also several other studies which are in concordance with Krantz et al. The Williams et al. study into whether anger was linked with heart disease interviewed 13,000 people with a ten question anger scale. At the time of the questioning, none of the participants suffered from heart disease. However when they were checked six years later it was found that those who scored highest on the anger scale were 2.69 times more likely to suffer from a heart attack than the others. This evidence strengthens the argument that stress is directly linked with illness, especially cardio-vascular issues.

Research has also shown that stress levels can have a negative effect on our immune system. In 1993, Cohen et al. used the “Viral challenge” technique on 400 volunteers. They were exposed to a common cold virus and asked to complete a perceived stress questionnaire. It was found that there was positive correlation between levels of stress and the likelihood of catching a cold, supporting the idea that stress lowers our resistance to illness. A final study which shows that stress has a negative effect on the immune system was conducted by Kiecolt-Glaser et al., 1984. They conducted tests on a series of students taking exams. It was found that their levels of T-cells (an immune system activity indicator) dropped during the exam period. During this time they would obviously be experiencing chronic and acute stressors.

On the other hand, Evans et al. 1994, conducted a study into the activity of the sIgA antibody in students. When asked to give a presentation to other students, a mild acute stressor, an increase in the sIgA antibody occurred. This suggested that the immune system actually improves when combating stress. However, it was found that sIgA levels did decrease during the several-week examination period. It was concluded that stress had two effects on the immune system: Up-regulation as a result of short term acute stressors, and down-regulation as a result of a chronic stressor. This conclusion is supported by the GAS model, which suggests that the body becomes exhausted from trying to cope with a long-term stressor.

In conclusion, all of the studies into stress’ effects on the cardio vascular system suggest that there is a direct link between high stress levels are illness. The higher your stress levels are, the more likely you are to experience heart problems and even heart disease. Also, high stress levels have a negative effect on the immune system, but only if the stress is chronic. During times of acute stress, the body reacts by trying to fight the stress, increase antibody levels. Overall, there is a direct link between stress and illness, especially chronic stress.

_{Mark achieved: 15/18}

_{References: “Psychology AS – The complete companion” by M. Cardwell & C. Flanagan.}