Cartesian ills

Descartes is still sowing confusion on the hospital ward. Neurologist Adam Zeman believes it is time to transcend the mind-body distinction
February 20, 1996

A young woman in her 20s-call her Jane-is admitted to our neurology ward because she has become weak down one side of her body. Like many such patients she has had some professional contact with medicine: Jane works as an assistant in a nursing home. Diagnoses of stroke, brain tumour and multiple sclerosis have been considered by the first few doctors she has seen. They have also been mooted with her. Anxiety runs high.

As she meets progressively more experienced specialists things fail to add up. Features which would be anticipated in paralysis are absent: Jane's reflexes, for instances, are normal. A sophisticated brain scan reveals nothing amiss. When troubles at home comes to light, suspicion grows that Jane does not have a neurological disorder at all.

Diagnoses of varying psychiatric sophistication are proposed: Jane is a) nuts, b) malingering, c) hysterical, d) displaying abnormal illness behaviour or e) suffering from a somatisation disorder. Most suggestions are at the less technical end of the spectrum: the training of physicians, curiously, tends to discourage psychiatric expertise. But on one point, at least, her doctors agree. Jane has a "functional" rather than an "organic" disorder.

Organic conditions are the real ones in neurological terms. All the conditions considered by Jane's first relay of doctors were organic. They have a specific anatomical and physiological basis. Something is amiss down the microscope. By contrast, functional disorders are pure disruptions of normal working: the organism itself remains intact. The distinction is attractive and, like my colleagues, I find it coming readily to my lips. On closer inspection it falls apart completely.

We usually mean one of three things when we wield this F-word. The first is the least reputable. "Functional" in this sense simply means incomprehensible. Faced with an unfamiliar symptom there is a temptation to suspect some sort of trickery. This can be dangerous. Few doctors have an encyclopaedic knowledge of their subject and new diseases are being described every week. Functional patients who turn out to have dire diseases are all too familiar to the negligence courts. With growing knowledge of the brain, a procession of peculiar "functional" disorders-from wry neck to writer's cramp-have come to be regarded as "organic."

The second sense of functional at least does more than dignify our ignorance. It is the proposition that functional disorders are ones which lack an anatomical or physiological basis. But it is absurd to suggest that there is no such basis for Jane's predicament. These days schoolchildren know that our thoughts and actions, the functions of the brain, have a physical basis, and students of psychology spend three years studying the anatomy and physiology of perfectly normal experiences and behaviour. Those addicted to the diagnosis of functional disorder might protest that they never meant to suggest that Jane's behaviour had no physical basis, merely that there was no underlying physical disorder. But there's clearly something the matter with Jane.

This leaves the third sense to fall back on: functional means psychological. The best explanation for Jane's behaviour is psychological: she could no longer bear the conflicts and demands at home and she needed a way out. Paralysis provided it. And much of her treatment should be psychological: reassurance, explanation, support. While this is true it provides precarious grounds for regarding her predicament as "non-organic."

All illness is psychosomatic, in the sense that every illness affects us psychologically. We consult our doctor because we have noticed that something is wrong. This is a psychological process: our expectations, anxieties, pain threshold and world outlook will all influence when and whether we seek help. Reassurance and explanation will be key elements in the management of the illness. This is psychological therapy, administered by any considerate physician. Doctors are not too concerned to prise the "functional" from the "organic" in the day-to-day care of the sick. But, when we puzzle over Jane's illness, we feel compelled to place her on one side or the other of the line between them: a frustrating task, because the line does not exist.

Oddly enough, it is often patients who are most devoted to this tenuous demarcation. If we suggest to Jane that she might benefit from an interview with a psychiatrist, we should expect trouble. The spectrum of likely reactions ranges from mild indignation to spitting rage. One of the more striking regular experiences of my working life is the look of utter astonishment on the face of a patient with florid hysteria when the possibility of a psychological explanation is raised for the first time. We shouldn't be too surprised by this-doctors themselves can't help drawing the incoherent distinction between respectable organic disease and suspect functional disorder.

The fundamental boundary at the back of the dubious contrast between the organic and the functional, is the line drawn long ago by Descartes: between body and mind. Their relationship is vexatious enough to philosophers. It is hardly surprising, therefore, that its obscurity should cloud the thinking of doctors and their patients.

There are, I grant you, differences between a problem like Jane's-most efficiently explained in terms of personality and stress-and an illness like a heart attack-best understood in terms of physiology (although it is worth remembering that personality and stress affect the risk of heart attacks, and that such illness, in its turn, may have effect on behaviour). But this distinction is most inaptly expressed by the contrast of function to organism.

You and I are organisms, packed with organs, "fearfully and wonderfully made." Our ailments are organic. The purpose of organisms, and their organs, is to function: so our ailments are functional too, or they would scarcely trouble us. Few disorders disrupt function more aggressively than, say, an epileptic seizure: but epilepsy is one of the neurologists' more cherished "organic" disorders. Schizophrenia is among the most profound afflictions of the human organism, in particular its brain: yet this has long been classified as a "functional psychosis." The notion that we can draw a hard and fast distinction between organic and functional disorders-with physical afflictions in the first category and psychological in the second, implies that behaviour and experience belong outside the world of organic nature, an implication belied by every consultation a neurologist, or a psychiatrist, makes.

It is revealing that we should draw this beguiling but forlorn distinction as we do-identifying the realm of the organic with what is physical and real, while its functions are relegated to the realm of psychology and illusion. Understanding the web of relationships between the physical and the psychological, healing the unnatural fracture between medicine and psychiatry, is one of the great challenges for the next millennium.