[Schizoaffective disorder: its nosographic significance]

This paper discusses the nosographic significance of schizoaffective disorder. Follow-up studies, genetic and familial studies, response to treatment studies, and neurobiological data are summarized and analysed. Methodological issues and importance of diagnostic criteria are also examined. Current opinion supports heterogeneity of schizoaffective disorder, among which schizophrenia variants or affective disorder variants. Some patients could present another disease. In that case, they are categorized in the sub-type "other" of the RDC classification for schizoaffective disorder.