The epidemiology of major affective disorders.

This article examined the methodological difficulties encountered in the epidemiological studies of affective disorders, the incidence and prevalence of these conditions, and the sociodemographic risk factors. The course of treated and untreated affective disorders is reviewed in terms of implications for treatment modalities and their evaluation, as well as factors suspected to be causally related to affective disorders (concomitants, predisposing and precipitating).