Objective - To set out the author's views of the role of epidemiology in social psychiatry and to illustrate this role with reference to affective disorders. Method - Review of work carried out in two areas; the bearing of gender and of age on rates of affective disorder. Results - The use of sociodemographic categories to define high risk groups suggests that affective disorder may be related strongly to role satisfaction and that age may have a pathoplastic effect on the form of disorder that overrides all but the strongest social influences. Conclusions - Epidemiology is an essential tool of the social psychiatrist, but its main strength is in clarifying the nature of the questions to be asked and suggesting new lines of investigation.

Objectives – The evaluation matrix recently proposed by Tansella and Thornicroft suggests that the field of social and epidemiological psychiatry has focussed more on the individual/patient level of mental health care services than the system level. Moreover, phenomena such as deinstitutionalisation have been examined more as clinical events than as social ones. The aims here are to deepen our understanding of deinstitutionalisation, particularly as regards the downsizing/closure and role of psychiatric hospitals. Methods – I begin by reviewing the manifest and latent functions of psychiatric hospitals. This is followed by a discussion of how these functions must be met by any comprehensive community-oriented system of mental health care for severely mentally ill patients. Also, in order to reframe the downsizing/closure of psychiatric hospitals as a social event for the field of social psychiatry and psychiatric epidemiology, I posit that the process of deinstitutionalisation is driven today by the same forces that were present at the outset of the movement. Results – I review four recent series of studies addressing primarily the outcomes, but also other aspects, of the downsizing/closure of psychiatric hospitals, with a view to illustrating the methods used, the results obtained and the blind angles missed in this research. Conclusions – Lessons are drawn on how to fill certain vacant cells of the matrix.