Schizophrenia and assaultive behaviour: the role of alcohol and drug abuse.

To assess the role of alcohol and drug abuse among schizophrenics with assaultive behaviour, we analysed case records of 38 patients who were responsible for a total of 71 violent offences between 1972 and 1986. They were identified from a population-based cohort of 644 individuals with schizophrenia hospitalized in Stockholm County during 1971. Fourteen of the 38 offenders abused alcohol and/or drugs and another 7 were probable abusers. These figures are higher than previously reported as regards abuse among schizophrenics. Most of the offences were performed by nonhospitalized patients who had been ill for many years. The nature of most of the violent incidents resembled that of offences committed by non-psychotic individuals. Our findings give further evidence for the role of abuse and social disintegration in assaultive behaviour among persons with schizophrenia.