History of violent behaviour and schizophrenia in different cultures. Analyses based on the WHO study on Determinants of Outcome of Severe Mental Disorders.

BACKGROUND: Information on patterns and correlates of the violent behaviour of individuals with schizophrenia is largely limited to populations in developed countries. Data from a World Health Organization epidemiological study of schizophrenia and related disorders, the Determinants of Outcome of Severe Mental Disorders (DOSMD), presented an opportunity to study patterns of violence across multinational settings.

METHOD: Centres in 10 countries participated in the DOSMD study. An incidence sample of 1017 patients with schizophrenia who had their first-in-lifetime contact with a helping agency as a result of their psychotic symptoms was obtained. Data were available on their history of violent behaviour, substance use, and demographics.

RESULTS: The occurrence rate of assault in the entire cohort was 20.6 per hundred, but the rate was three times higher in the developing countries (31.5 per hundred) than in developed countries (10.5 per hundred). History of assault was associated with positive symptoms, such as excitement and auditory hallucinations, and with serious alcohol problems.

CONCLUSIONS: The cultural context and the specific characteristics of the disease in individuals with schizophrenia may interactively affect rates of violent behaviour.