Research done by Holmes and Rahe (1967) with the Social Readjustment Rating Scale (SRRS) to measure the extent of adjustment required by certain situations in life events such as moving home, going on holiday or death of a loved one showed that those who scored above a certain level on the SRRS often developed a physical illness within a year. In a study by Kielcot-Glaser et al. (1995) compared the wound healing rate of a group of high stress women caring for relatives with Alzheimer’s disease and a stress free matched group. They noticed that in the group of high stress women, complete wound healing took nine days longer than the stress free group showing that stress impairs the body’s ability to heal itself when stressed and more importantly had potential consequences for those people who are stressed and needing to undergo major surgery and then recover from it.
Another researcher who found a supportive link between stress and illness was Russek (1962), who’s research found a link between that of work-related stress and heart disease. He tested a group of medical professionals and labelled them as high-stress or low-stress according to their role, with General Practioner’s having high levels of stress and Dermatologists having low stress. The study showed General Practioner’s had the greatest rate of heart disease (11.9%) where as dermatologists had the least heart disease (3.2%). This showed that there is a link between heart disease and stress within a job. However the dermatologists may have a higher stress job than predicted, also professional lives may not be the only cause of stress e.g. personal lives or personal issues may also have affect stress levels.
In 1936 a Canadian physiologist Hans Seyle introduced his theory of ‘General Adaptation Syndrome’ (GAS). Through research done on rats in adverse conditions Seyle was able to develop this theory which was useful in predicting the body’s physiological responses to stress. General adaptation Syndrome (GAS) describes the three phases of how the body reacts to stress. In his work, Selye developed the theory that stress is a major cause of disease because chronic (long term) stress causes long term chemical imbalances which are harmful to the body. The initial reaction is the fight or flight stage (alarm stage) which is the body’s first mechanism to respond to the stressors, he observed that the body would respond to any external biological source of stress with a predictable biological pattern in an attempt to restore the body’s internal homeostatic balance. During the ‘Alarm’ phase the part of the brain called the hypothalamus detects stress and in turn activates the sympathetic division of the nervous system which releases hormones cortisol, adrenaline and noradrenaline to provide the body with instant energy to combat the stressors. During the alarm stage everything in the body is working as it should as the hormones have jolted the body with the instant energy, however if this instant energy is not physically used by the body it can become harmful as too much adrenaline results in an increase in blood pressure which can damage blood vessels to the heart and brain, a major risk for heart attacks and strokes. Excessive production of the cortisol hormone can also cause damage to cells and muscle tissue as it causes organs such as the heart to become sensitized as well as the cardiovascular system. Moving to the second phase of ‘GAS’ known as the ‘Resistance’ stage which is almost immediately after the ‘alarm stage’ starts the body is possibly coming to terms or resolving the stress. Homeostasis begins restoring balance in the body and a period of recovery for repair and renewal takes place, however if the stress persists the body adapts in a continued effort in resistance and remains in a state of arousal. Problems begin to arise when this stage is repeated too often and there is little or no recovery. This progresses to the final phase ‘Exhaustion’ where the stress has persisted for some time and the body’s ability to resist is lost as its adaptation energy supply is exhausted. This is sometimes referred to as adrenal fatigue, maladaptation or dysfunction where stress levels go up and remain high. This phase of GAS is the most dangerous to the health as the person no longer has the adaptation stores to fight off the stress and could result in serious stress related illness as the chemical balances caused as a result of the body trying to cope with stress. Chronic stress will involve repeated episodes of increases in heart rate and blood pressure, which in turn produce increases in plaque formation within the cardiovascular system. Stress also produces an increase in blood cholesterol levels, through the action of adrenaline and nor adrenaline on the release of free fatty acids. This produces a clumping together of cholesterol particles which lead to clots in the blood and in the artery walls and blocking of the arteries. As a result of the raised heart rate there is a more rapid build up of cholesterol on artery walls. High blood pressure results in small lesions on the artery walls, and cholesterol tends to get trapped in these lesions (Holmes, 1994). Goetsch & Fuller (1995) referred to studies that show decreases in the activity of lymphocytes among medical students during their final exams. Lymphocytes are particular type of white blood cell, which normally fights off viruses and cancer cells. Research done by Jemont et al (1985), found that students during exams had lower counts of antibodies which assisted in fighting off colds and flu.
The immune system is also capable of triggering this chain of biological events as it has a direct link to the hypothalamus. When the immune system is activated to fight illness or infection, it sends a signal to the hypothalamus to produce its stress hormones, including cortisol. The flow of hormones, in turn shuts off the immune response. This negative-feedback loop allows a short burst of immune activity, but prevents the immune system from over-activity. In this way some stress can be beneficial for the individual. But chronic stress produces such a constant flow of cortisol that the immune system is dampened too much. This helps explain how stress makes us ill (Sternberg, 2000). In a review of the scientific literature on the relationship between and disease, Carnegie Mellon University psychologist Sheldon Cohen has found that stress is a contributing factor in human disease, and in particular , cardiovascular disease and HIV/AIDS. Cohen's findings were published in the Oct. 10 issue of the Journal of the American Medical Association (JAMA). As recently as April (2012) further research done at Carnegie Mellon University by Sheldon Cohen and published in the Proceedings of the National Academy of Sciences shows for the first time that the effects of psychological stress on the body’s ability to control inflammation can further the development and advancement of illness and disease.
In conclusion we see that all the various studies done some way or the other provide evidence to suggest a link between illness and stress, and shows that the more stress the person is under the more likely he or she is to becoming ill. Long term stress can disable the body’s ability to cope as a result of the chemical imbalances from within. But more importantly how an individual deals with stress or stressors also determines to some extent whether they are at risk to illness. The negative effects of stress on the functioning of the immune system have been found in many research studies. Therefore, the results in this area of research are extremely reliable. Even though a lot of research in this area is correlational, it probably is the case that there is an unintended relationship between stress and the functioning of the immune system. However, studies typically talk about group differences or correlations such as medical students or people who have been bereaved, etc. within those groups, there are large individual differences, and some people experiencing bereavement for example do not show impaired immune system function. We know that there are important individual differences such as gender, but we don’t know why these occur. An increasing body of evidence suggests there is a relative role for acute and chronic stress in many medical disorders and psychiatric states. Methods of measuring and assessing stress factors need to also appraise the patients coping and adaptive mechanisms.
References:
Carnegie Mellon University (2012, April 2). How stress influences disease: Study reveals inflammation as the culprit. ScienceDaily
Class Handout 7 Nov 2012, Saker. D PHYSIOLOGICAL PSYCHOLOGY- STRESS
Gross.R, Mcilveen R, Coolican H, Clamp A & Russell J, (2005). 'Stress'. In: (ed), PSYCHOLOGY A New Introduction FOR A LEVEL. 2nd ed. England: GreenGate. pp.70-77.
Journal Reference:Sheldon Cohen, Denise Janicki-Deverts, William J. Doyle, Gregory E. Miller, Ellen Frank, Bruce S. Rabin, and Ronald B. Turner. Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. PNAS, April 2, 2012 DOI:
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