Predicting violence in schizophrenia: a prospective study

Background: People with schizophrenia are more violent than the general population, but this increased risk is attributable to the actions of a small subgroup. Identifying those at risk has become an essential part of clinical practice. Aims: To estimate the risk factors for assault in patients with schizophrenia. Methods: Two hundred seventy-one patients with schizophrenia were interviewed using an extensive battery of instruments. Assault was measured from multiple data sources over the next 2 years and criminal records were obtained. Multiple sociodemographic and clinical variables measured at baseline were examined as possible predictors of assault during follow-up. Results: Sixty-nine (25%) patients committed assault during the 2-year follow-up. The model that best predicted assault included a history of recent assault (OR 2.33, 95% CI 1.17–4.61), a previous violent conviction (OR 2.02, 95% CI 1.04–3.87), having received special education (OR 2.76, 95% CI 1.22–6.26) and alcohol abuse (OR 3.55, 95% CI 1.24–10.2). Conclusions: Previously established risk factors including a history of violence and alcohol abuse are replicated in this study. Although low premorbid IQ did not predict violence, a need for special education did.