COMMENT:MORE THAN JUST TIRED

It seemed unimaginable a few years ago. Despite the growing evidence indicating that ME is a distinct clinical entity, and just months after the World Health Organization recognized ME by adding it to its list of diseases doctors appear to have decid

Admittedly, the new name is easier to spell and much easier to pronounce than myalgic encephalitis. However, CFS is simply not an illness. It’s not even a disorder. CFS is an umbrella term. It actually covers a number of different conditions, all of which have one symptom in common: chronic fatigue.

In recent months the name has been variously used to describe cases of chronic fatigue caused by lifestyle factors (eg having two jobs), stress, lack of physical fitness and a variety of psychiatric disorders. It also covers less common conditions including post viral states (except hepatitis), undiagnosed or stubborn cases of Lyme disease (an acute form of arthritis, thought to be transmitted by a tick), giardiasis (parasitic infection of the intestines) and allergies, as well as reactions to poisonous substances.

To complicate matters even further, the original concept of CFS has changed. In the past, the name referred to a disabling condition lasting at least six months which made patients feel exhausted and ill. Nowadays it can include people who have felt tired for just two weeks (Public Health Reports 1992; 107:514).

To orthodox scientists like myself, lumping disorders together on the basis of one shared symptom is a retrograde step which undermines good science and is unlikely to benefit patients. Can you imagine what would have happened had doctors decided to get rid of the term migraine? Would scientists ever have discovered the complexity of this condition if they had not distinguished it from tension headaches? How much sympathy would you have for patients if you had never read about the severity of the pain, the nausea and the sickness? Well, that’s what is happening to ME.

Whereas ME was an illness characterized by periods of disabling exhaustion, CFS is more often described in terms of tiredness and lethargy. Indeed, one doctor dismissed CFS patients as people who “expect to feel 100 per cent, 100 per cent of the time” (Pulse, 10 November 1990).

The causes are also different. While ME was linked to a persistent infection, CFS is said to result from the patients’ fear of (normal) fatigue, which leads them to avoid all activities, and become passive and helpless (Journal of Neurology, Neurosurgery and Psychiatry, 1991; 54: 153). I can quite understand why doctors, who’ve all survived the exhaustion and stress of their junior hospital years, might not be terribly impressed by a condition which amounts to little more than mental and physical fatigue plus abnormal illness behaviour.

Read about CFS in any medical publication and the article will almost certainly mention the high rates of psychiatric disorders, and the significant improvements on graded exercise programmes (Pulse, 6 February 1993). What the articles don’t mention includes the following:

The term CFS was originally adopted in the US because doctors there thought that the illness they were seeing was not ME. According to a recent study, many American researchers still believe the two to be different (Levine P H et al, Archives of Internal Medicine, 1992; 152: 1611).

Although the rates of depression in CFS are high, the figures for ME and disorders like CFIDS (chronic fatigue and immune dysfunction syndrome) tend to be much lower (average is 22.8 per cent), and similar to those of patients with other physical diseases (average of 10 recent estimates is 26.8 per cent). Thus the high rates of psychiatric disorders in ME are either a myth or the psychiatrists are only seeing atypical cases. In terms of CFS, the rates of psychiatric illness are what one would expect, given the disorders it covers.

There has been only one controlled trial of graded exercise therapy in ME, and it showed that this treatment was no more effective than a placebo (Am. J. Med, 1993, 95, 197). The study which doctors tend to quote as their reason for using graded exercise was not controlled, it was not restricted to people with ME, many patients were also taking antidepressants, and a large number of patients dropped out. (What’s more, a separate study on royal jelly showed that to be just as effective.)

The fact that the symptoms of ME tend to fluctuate argues against the idea that they are caused by a lack of physical fitness. If the latter played a major role, patients would generally get worse with time and on the whole, they don’t. It’s also hard to explain symptoms like intolerance to alcohol in terms of a lack of fitness or, for that matter, depression.

The most popular theories, which attribute ME/CFS to inactivity, depression and a desire to escape the rat race, cannot explain findings such as the presence of viral particles in the brain and muscles, the high rates of allergic type reactions and the evidence of immunological dysfunction (CIBA Symposium 173, Wiley and Sons, 1993).

Unfortunately, if we don’t distinguish between CFS and ME it’s unlikely that we will find out much more about the latter. This is because out of 100 patients with CFS diagnosed according to the current British criteria, perhaps only 5 will have ME. Thus if 90 per cent of the ME group have a physical abnormality, this will constitute only 4 per cent of the whole sample. Observers will rightly note that the finding is untypical of people with CFS and it will be dismissed.

To summarize, CFS is a scientific nightmare which confuses doctors and makes the interpretation of research near impossible. As scientists, we should consider all the evidence, and at the moment, we are losing a lot of information by not keeping disorders like ME and fibromyalgia separate. ME deserves to be taken seriously. CFS will stop us from doing just that.