John Brown, and the Nonspecific Component of Human Sickness

JOHN BROWN, AND THE NONSPECIFIC COMPONENT OF HUMAN SICKNESS W. R. TROTTER, D.M., F.R.C.P.* Medicine has advanced by isolating symptom complexes and searching for causal factors associated with them. No progress was possible until the vast, bewildering problem of human sickness had been reduced in this way to more manageable units, which then became amenable to study in detail. The idea behind this extremely effective manoeuvre has been called "the concept of specificity" by Lindeboom [1], in a paper in which he outlined the history of the idea. The first effective use of this procedure was in the eighteenth century, when James Lind (1716-1794) showed that scurvy was a specific disease caused by lack of fresh vegetables, and George Baker (1722-1809) showed that "Devonshire colic" was a specific disease caused by lead poisoning. But it only became applicable on a large scale with the identification of specific microorganisms as the causes of specific diseases. Nearly all subsequent progress has been won by the use of the same general type of method. The enormous success of this method has engendered the implicit belief that all the problems presented by human sickness will ultimately be soluble in the same way. This belief implies that patients are only sick because they suffer from one of a number of specific diseases, all of which, when we have become a little smarter, we shall be able to identify and treat. This sounds a little too good to be true; although there must still be many specific diseases waiting to be recognised, there is also likely to be a residue of human sickness which obstinately refuses to be categorized in this way. Even now, there are areas of medicine in which the definition of specific diseases has been difficult and unsatisfactory. In psychiatry, for example, it has been impossible to develop diagnostic criteria anything like as stringent as those used in somatic disorders, and in consequence 'Consulting Physician. University College Hospital, London, England. Address: Surrey End, Tennyson's Lane, Haslemere, Surrey GU27 3AF, England.© 1978 by The University of Chicago. 0031-5982/78/2102-0008J01.00 258 J W. R. Trotter ¦ John Brown most psychiatric diseases have a rather woolly look about them. It seems reasonable to suspect that a good deal of psychiatric disability is due not to any specific disease, but rather to a disproportion between patients' innate abilities and the demands of the social environment. Another area in which the search for specific diseases has not been conspicuously successful is that of senescence. The assumption behind much research in this field has been that the process of aging is simply a matter of acquiring a succession of age-related specific diseases. When these have been identified and their causes found (it is implied), appropriate treatment will then abolish old age. This is, to say the least, an improbable scenario, and this is perhaps one ofthe reasons why progress in this field has so far not been particularly impressive. The relative lack of success of this approach in psychiatry and geriatrics is, of course, no reason for advocating the abandonment of the search for specific diseases. But it may well be an indication that this particular method of attack on the problems of human sickness will one day reach its limits and that we ought to be prepared with a contingency plan for dealing with those which still remain. In this connection, it may be helpful to look back to the time before the concept of specificity came to dominate the scene. The eighteenth century was a formative period in medical epistemology, when various alternatives to the discredited Galenical system were tried out. Some were manifest failures, like the artificial nosologies which assumed that diseases could be classified like plants. Of more interest were the systems which treated sickness as a disturbance of a physiological equilibrium. These, too, were failures, largely because the physiology on which they were based was fallacious. The approach of these system makers to the general problem of human sickness is nevertheless of interest in the present context. One of the best defined, and also one of the most influential, of the eighteenth-century...