Substance abuse in schizophrenia: a review of the literature and a study of correlates in Sweden

The purpose of the current study is twofold. (a) to provide an overall synt hesis of recent research on substance abuse in schizophrenia and (b) to pre sent findings in a Swedish patient sample. Studies conducted since 1990 hav e found a wide range of abuse prevalence rates, with male gender and younge r age as primary correlates. Less certainty exists regarding substance abus e as an independent risk factor for schizophrenia and its further impact on illness course. In a sample of 87 patients attending a psychiatric clinic in Malmo, lifetime prevalence of substance abuse was 48.3%, with abuse debu t primarily preceding first contact for psychotic symptoms. Significant cor relates of abuse were male gender, family history of substance abuse, and i ncreased rates of hospitalization and criminality, with poorer outcome foun d in previous as well as current abusers. Alcohol abuse, either solely or i n combination with other substances, was the main type of substance abuse. Although the specific factors (social, behavioural, genetic) that predispos e schizophrenic patients to substance abuse remain unclear, the predominant ly male profile of abusers might suggest a link between substance abuse and the poorer clinical outcome frequently observed, especially in male schizo phrenic patients. (C) 2001 Elsevier Science B.V, All rights reserved.