A critique of biological psychiatry

Biological psychiatry has established itself as a fully fledged branch of medical science. Originally a subject which developed at the borderline where psychiatry meets the biological sciences (especially endocrinology, neurochemistry and clinical biochemistry), it has now budded-off, taken root, and developed its own journals, theories, practices and proofs: even its own training. In what follows, I use the term biological psychiatry in this restricted sense, which gives the subject a fairly short history: the great bulk of research has been done since the 1970s. Biological psychiatry can be defined as the attempt to discover biological correlates of psychiatric disorder, with the aim of establishing aetiology, therapy and prognosis. This is a much narrower definition than that of Samuel Guze in his recent article in Psychological Medicine (1989), where he uses the term to refer to all that is valid and useful in the realm of psychiatric practice in effect, if it is not biological then it is not good psychiatry. Guze's article is a highly ' whiggish' account describing the impressive progress of psychiatry up until now, with a confident extrapolation of this trend into the future. While differences in the scope of definition mean that the two essays are not strictly comparable they nevertheless adopt a clearly different standpoint, and I will contrast my views with those of Professor Guze where it helps to clarify them. Biological psychiatry is not without its critics, and any 'whiggish' history of progress requires a ' revisionist' response which calls this progress into question. It seems timely to take a sceptic's view of things, to play the devil's advocate perhaps. I am not so impressed as Professor Guze by the supposed progress in this field, and I am also concerned that we may be adopting a mistaken way of interpreting biological data in psychiatry. In this editorial I aim to take on board some of the less flattering things said about us by fellow biologists, psychologists and philosophers. This will be seen to lead on to philosophical considerations of the scope and status of biological psychiatry, with the aim of discovering how best to interpret the subject. Aside from its innate attractions, common to all branches of science, the ultimate promise of biological psychiatry is that it will, sooner or later, lead to improved therapy. My critique of biological psychiatry springs from the simple observation that the most important physical therapeutic advances (roughly speaking, in order, the development of ECT, phenothiazines, tricyclics and lithium) were discovered more or less by accident and before the advent of biological psychiatry as a distinct speciality. In fact the therapeutic advances were themselves the major stimulants of theory and subsequent biological research: for example the discovery of phenothiazines led to the dopaminergic hypothesis of schizophrenia, while tricyclics and MAOIs led to the amine hypothesis of depression. In other words, theory has been highly effective at fitting itself to past experiments, but relatively useless at predicting the results of future experiments. My perspective is therefore coloured by a sense of disappointment, rather than pride, at the achievements of the subject. And my aim is to explore some of the reasons which lie behind this sluggish rate of progress. The first problem is the sheer difficulty of doing experiments in biological psychiatry. This is the purist's reductionist critique, and is widespread among basic biological scientists, particularly those who work on single cells. The story runs that because humans are not animals (let alone single cells), we cannot do the experiments we want or need to. For example, it is not desirable to give highly toxic drugs, leave patients untreated to study the natural course of illness, or to kill people in order to reach inaccessible tissues such as the brain: these are the ethical constraints. Then there is the lack