Background - By the mid-1960s, the importance of socio-economic status for schizophrenia had been demonstrated in terms of differences between social-class groups in prevalence and incidence rates, illness course and outcome, and treatment experience. In the causation - selection debate, however, opinion had swung in favour of the selection hypothesis. Aims - To reassess evidence on the social-class distribution of schizophrenia in Britain, and to compare this body of research with population-based studies of schizophrenia risk in socially disadvantaged ethnic minorities. Method - Systematic review of medical and psychological data-bases. Results - Epidemiological research, while confirming the importance of premorbid social decline, has also provided support for the environmental 'breeder' hypothesis. High psychosis rates have been confirmed in ethnic minorities; in particular among Afro-Caribbean and other Black immigrants whose low social status cannot be accounted for by selective downward social drift or segregation. Conclusions - There are striking parallels, both in the epidemiology of schizophrenia and in social characteristics, between the lower-class indigenous groups highlighted by earlier psychiatric surveys and African-Caribbean populations in Britain's inner cities today. These similarities underline the need for a broader perspective in the search for environmental risk factors.

Socio-economic status Social class schizophrenia Ethnic status immigrant mental health Psychosis

immigrant schizophrenia human risk assessment psychosis medical research data base comparative study Environment ethnology social status environmental factor risk factor Review United Kingdom social class psychiatry systematic review health survey