Suicide prevention effects associated with clozapine therapy in schizophrenia and schizoaffective disorder

Objective and methods: Suicide is a significant cause of death among patients with schizophrenia and schizoaffective disorder, affecting some 10 to 15 percent of these patients. This study examined annual suicide rates over a two-year period (1993-1995) among more than 30,000 patients with schizophrenia and schizoaffective disorder who received services from the Texas Department of Mental Health and Mental Retardation and suicide rates over a six-year period (1991-1996) among a subgroup of patients treated with clozapine. Results: The annual suicide rate for all patients with schizophrenia and schizoaffective disorder was 63.1 per 100,000 patients, approximately five times higher than in the general population. In contrast, only one suicide occurred in six years among patients treated with clozapine who were of similar diagnosis, age, and sex, for a suicide rate of about 12.7 per 100,000 patients per year. This rate is similar to the 15.7 per 100,000 patients per year for all U.S. patients treated with clozapine, calculated from data reported as of June 1996 to the clozapine national registry system maintained by Novartis Pharmaceuticals Corporation, the U.S. manufacturer of clozapine. Conclusions: The study results suggest that clozapine therapy is associated with a reduced risk of suicide among patients with schizophrenia and schizoaffective disorder.