ABSTRACT
Since first given life by Kraepelin and Bleuler almost 100 years ago (see Chapter 1 by Boyle in this volume), the concept of 'schizophrenia' has become so pervasive that approximately 1 per cent of individuals in western countries can be expected to be labelled 'schizophrenic' at some time in their lives (Torrey 1987). Many of these people will spend a considerable portion of their adult lives in psychiatric hospitals, will be treated with powerful medications, and will live impoverished, marginalized existences (see Chapters 8 and 3 by Pilgrim, and Barham and Hayward respectively, in this volume). Because of the economic, social, and personal costs of the hypothesized disorder, research continues to be carried out into schizophrenia on a massive scale and numerous theories have been proposed by scientists to account for schizophrenic behaviour. Hypothesized causes of schizophrenia include genetic endowment (for example, Gottesman and Shields 1982; see Chapter 4 by Marshall in this volume), abnormalities of brain structure or brain biochemistry (Pincus and Tucker 1978; Green and Costain 1981; see Chapter 5 by jackson in this volume), diet (Singh and Kay 1976), season of birth (Watson et al. 1982) linked to hypothetical viral agents (Crow 1984), social stress (Faris and Dunham 1939), life events (Brown and Birley 1968) and family structure (Bateson et al. 1956). Indeed, almost every variable known to affect human behaviour has, at one time or another, been held to be important in the aetiology of schizophrenia. Although it is not possible within the confines of the present chapter to review the evidence pertaining to these hypotheses, it is fair to say that each of the theories is favoured by some researchers yet rejected by others. Thus, despite the fact that there has been a tendency in recent years to talk about schizophrenia as if it were a neurological condition (Eccleston 1986), few would wish to claim that the causes of schizophrenia are known. Indeed, the sceptic may be inclined to ask whether nearly 100 years of multidisciplinary research into the aetiology of schizophrenia has yielded any substantial progress. (Compare, for example, the rapid progress that has been made in AIDS research in just a few years; cf. Connor and Kingman 1988.) Why, then, has schizophrenia proved so resistant to scientific effort?
