[Schizophrenia and substance dependence].

A review of epidemiological data regarding the prevalence of substance abuse in schizophrenia and vice versa points out differences which are hard to interpret, owing to inconsistent sampling procedures and to the application of different diagnostic criteria. Stimulant abuse in schizophrenics has apparently increased over the years, eventually alcoholic abuse, whereas no increase is evidenced for cannabis abuse. Patients with dual diagnosis have an increased risk for morbidity and mortality, for psychotic relapse and for social disintegration. No increased risk for schizophrenic psychosis is found for drug abusers. Possible explanations why schizophrenics could show an increased susceptibility to become substance abusers are discussed, and therapeutic recommendations added.