The Sickening Mind: Brain, Behaviour, Immunity and Disease. Paul Martin

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СКАЧАТЬ meat of the problem. No one yet knows for certain what causes CFS. The arguments continue to rage and there are major divisions of opinion within the medical community. But what characterizes the whole debate – especially as it is portrayed in the popular media – is the implicit distinction between physical causes, which are held to be genuine, and psychological causes, which are held to be suspect.

      With a few honourable exceptions, expert opinion on CFS divides neatly into two opposing camps. In one camp are those who maintain that CFS has a physical cause such as a virus or an immunological disorder. According to this view, the depression and other psychological symptoms that characterize CFS are consequences rather than causes of the underlying physical disorder.

      In the opposing camp are those who argue instead that CFS is fundamentally a psychological disorder. According to this view, the physical symptoms such as exhaustion, muscle pains, fever and malaise, are manifestations of an underlying psychiatric problem.

      Which view is correct? You may not be surprised to find that both are at least partially true. Many CFS sufferers have symptoms that match the diagnostic criteria for psychiatric disorders and organic disease. The evidence is undoubtedly complex and equivocal but it points towards one conclusion: that chronic fatigue syndrome has both physical and psychological components. Let us examine some of this evidence.

      Most cases of CFS are preceded by a viral infection of one kind or another, and there have been repeated suggestions that a virus might lie at the root of the syndrome. For a long time the prime candidate was the Epstein-Barr virus, a member of the herpes virus family which is also responsible for glandular fever. During the 1980s chronic fatigue syndrome was widely referred to as ‘chronic Epstein-Barr virus infection’, as though its viral origins had been firmly established. Other candidates have included retroviruses (of which HIV is an example) and polio-like viruses called enteroviruses.

      There is as yet no conclusive evidence to support the viral theory and it has therefore fallen out of favour. But even if viruses are not the prime cause of CFS, it remains highly plausible that a viral infection might help to trigger or precipitate the syndrome when other causal factors are also present.

      Several other physical causes besides viruses have been proposed. One theory maintains that the primary symptoms of CFS are produced by hyperventilation – that is, abnormally rapid breathing. The evidence, however, is once again scant. Only a minority of CFS sufferers hyperventilate. On another tack, research at Johns Hopkins University in Baltimore has indicated that certain types of chronic fatigue (though not necessarily all cases of CFS) might result from abnormally low blood pressure. Yet another suggestion has been that CFS stems from a form of neurobiological disorder. One study revealed that more than a quarter of CFS patients had abnormal brain scans, and subtle changes have been found in the levels of neurotransmitter substances in the brain.

      At present, the most favoured physical theories about the origins of CFS revolve around the immune system. There is growing support for the view that the symptoms of CFS result from a perturbation or abnormality in the sufferer’s immune system. This immunological malfunction, it is argued, may be triggered by a viral infection which somehow throws the immune system out of kilter.

      Evidence that CFS involves an immunological disorder is accumulating rapidly. Within the past few years various abnormalities have been found in the immune systems of CFS sufferers. These include alterations in the activity and surface structure of two important types of white blood cells: the natural killer cells and T-lymphocytes. (You will be hearing much more about these cells in later chapters.) It is becoming increasingly evident that CFS is associated with, if not directly caused by, a persistent, low-level activation of the immune system.

      If CFS really is an immunological disorder then why do some perfectly sensible scientists and physicians persist in regarding it as primarily a psychological disorder? They persist because there is highly respectable evidence to support their viewpoint as well.

      Several of the symptoms associated with CFS are also seen in psychiatric illnesses, notably depressive and anxiety disorders. A substantial proportion of those who seek medical help for chronic fatigue turn out to have a recognizable psychological problem. The authoritative Centers For Disease Control and Prevention in the USA has concluded that approximately 45 per cent of all CFS sufferers have some form of identifiable psychiatric disorder before the onset of CFS. Researchers at the University of Connecticut School of Medicine found that as many as three out of four of the chronic fatigue cases they examined could be more easily explained by psychiatric problems such as depression. To add to the picture that the mind plays a central role in the illness, Australian researchers have discovered that CFS patients exhibit significantly more signs of hypochondria than other medical patients.

      Psychological theories of CFS have tended to focus on depression. Over half of all CFS sufferers exhibit clear signs of clinical depression. Often the depression appears to have preceded the chronic fatigue, suggesting that it might be a cause rather than a consequence of the syndrome. Severe depression is usually accompanied by prolonged reductions in physical activity which could, in turn, lead to a debilitating decline in muscle function. People who lie in bed for long periods become physically weak. The sleep disturbances that typify some depressive disorders might also exacerbate the sufferer’s fatigue. Furthermore, it is known that severe depressive disorders are associated with changes in the immune system.

      But hold fast. It is equally clear that many CFS sufferers become depressed as a consequence of their illness. It is hardly surprising that those suffering from a debilitating but unexplained illness should become depressed and abnormally preoccupied with their health. Although more women than men suffer from CFS this should not be interpreted as evidence that CFS is primarily a psychological disorder, as a few sexist pundits have implied. There are several perfectly respectable organic diseases, such as rheumatoid arthritis, which show a marked preference for one sex over the other.

      At present it is probably safe to conclude that the case for CFS being primarily a psychological disorder remains unproven. The evidence for some sort of immunological malfunction is too good to dismiss. There is, however, no doubt that CFS sufferers’ psychological reactions to their illness do have an important bearing on their wellbeing and recovery. Whether depression is a cause or an effect of the syndrome, it becomes a major problem in its own right and can seriously impede recovery.

      The controversy over CFS is further complicated by the attitudes of those who suffer from it. People who are afflicted by a serious and debilitating disorder such as CFS want their illness to be publicly recognized as having a medically respectable cause. For most people this means a physical cause, such as a virus or an immunological disorder, rather than a psychological cause. Any suggestion that their symptoms might result from a psychiatric problem tends to provoke outrage.

      This attitude is understandable. Talk of psychological causes often carries with it an unjustifiable connotation that the illness is not quite genuine. There is usually a strong whiff of ‘get a grip on yourself and snap out of it’ in the air. Moreover, even in the late twentieth century there is still a wholly unreasonable stigma attached to mental illness. The average person would rather admit to having a physical illness, albeit a vague ‘mystery’ virus or obscure immunological malfunction, for this absolves them of any accusations of malingering, neuroticism or weakness of character. One unfortunate outcome of this desire for a physical explanation is the tendency, in some countries at least, for CFS sufferers to shop around until they find a physician who will give them the diagnosis they want.

      Ironically, it turns out that the CFS sufferers who believe most strongly in a purely physical explanation have greater difficulty in recovering from their illness. This may be because they fail to confront and deal with the psychological problems that invariably accompany the illness.

      Evidence to support this conclusion has come from a study conducted by Michael Sharpe and colleagues СКАЧАТЬ