A study which shows the effects of stress on the immune system is Kiecolt Glaser’s study which was constructed in 1984. The aim of this study was to investigate whether the stress of important examinations has an effect on the functioning of the immune system. The procedures which were carried out, was firstly 75 medical students were used in a natural experiment, blood samples were taken one month before there final examinations when there was relatively low stress, and during the examinations when there was relatively high stress, the immune system functions were assessed by measuring the NK cell activity in the blood samples, the students were also given questionnaires to assess psychological variables such as life events and loneliness. The finding were that NK cell activity was significantly reduced in the second round in the second blood sample, taken during their final examinations, compared with the first sample which was taken one month before their final examinations, NK cell activity was most reduced in participants who also reported high levels of life events and loneliness. Glaser concluded that examination stress reduces immune function, potentially leaving the individual vulnerable to illness infections, also that the immune function is also affected by psychological variables such as the stress of life events and feelings of loneliness. These long term stressors may make individuals more vulnerable to the added effect of short term stressors such as examinations. Overall this was essentially a correlated study, so a strong conclusion about a cause and effect relationship cannot be drawn, also it was a natural experiment using a natural source of stress and therefore had reasonable ecological validity, but the students may be a special group of generalization should be made with caution. Glaser also said even short term predictable and relatively benign stressors can increase vulnerability to illness. She included individuals who have stronger close personal relationships are less likely to show adverse immunological consequences when stressed, for example when she followed students through exams she found lonelier students had lower NK cell activity than those were not lonely. In Glaser’s studies she said the most consistent gender differences occurred in response to material conflict, for instance she said the relationship between adverse hormonal and immunological changes, and negative or hostile behaviours, were stronger for women than men.
It is said suppression of the immune system need not necessarily lead to illness and disease if immune function remains within normal range. Even if it is not, you still have to be exposed to an infectious agent for illness to develop. Cohen (1993) demonstrated this in a classic study. Participants filled in questionnaires on negative life events, how stressed they felt and the degree of negative emotions they felt. The participants were then exposed to low doses of common cold virus, 82% of the 394 participants became infected with the cold virus, and infection was highly correlated with their stress index score, for instance the higher their score the more likely they were to become infected.
Research evidence suggests that there is relationship between stress and physical illness, and in some cases this comes about through immunosuppressant.
There are many way to which our body responds to stress also methods used to reduce stress, for instance the way our body responds to stress involves three main stages. The first stage is the central nervous system which consists of the brain and the spinal cord and its job is to co ordinate all body functions. A small structure of the brain known as the hypothalamus plays a major role in the stress response. The second stage is the autonomic nervous system in this the ANS connects the CNS to the body’s internal organs, glands and smooth muscles and its function is to regulate internal bodily processes. The ANS is divided into two functions- the sympathetic branch which comes into play when we are alert and aroused and prepares the body to expend energy, and the parasympathetic branch which slows the system down and stores energy. It is the sympathetic branch of the ANS which is involved in the stress response and is responsible for things such as the increase in the heart rate, blood pressure and sweat gland activity. The third and final stage is the endocrine system this is controlled by the hypothalamus and during the stress response the endocrine gland secretes hormones. The pituitary gland secretes hormones that control the other glands, the most important in the stress response being the adrenal glands which are responsible for producing the adrenaline rush which is often felt in stressful situations.
There are many methods used to reduce stress, some methods are physiological while the other are psychological. Lazarus and Followman distinguished between problem and emotion focused strategies. There was direct action where the problem was focused, in some case the stressor can be removed. There is also other problems where you do something else to take you mind off the problem, there is also taking control this is where a person who feels in control suffers less harmful consequences of stress, another method used to reduce stress is biofeedback and relaxation where by the emotion is focused. Other emotion focused strategies are anxiolytic drugs such as Librium and Valium act directly on ANS and synapses. Stress management programmes such as time management or assertiveness training teach people to pace themselves better and avoid stress, while a physical activity and exercise promote better circulation which strengthens the heart, Goldwater and Collins found that exercise was positively to decrease anxiety.
In conclusion I have realised that stress has an effect on the body both mentally and physically, this could alter the perception of the way the person see life. Glaser found that certain stress reduces the immune function, potentially leaving the individual more vulnerable to the illness and infections, she also verifies that the immune functions is also affected psychological variables such as stress of life event and feelings of loneliness.
