Clozapine superior to olanzapine, haloperidol in assaultive schizophrenia

Clozapine is the best treatment for violent schizophrenia patients with conduct disorder as compared with olanzapine and haloperidol, claims a recent study.

“This study is the first to examine the effect of clozapine in violent schizophrenia patients with conduct disorder,” the authors said.

Ninety-nine physically assaultive schizophrenia patients were randomized to receive clozapine, olanzapine, or haloperidol in a 12-week double-blind trial. Participants were characterized based on the presence or absence of conduct disorder before age 15. The authors recorded assaults and scored their frequency and severity on the Modified Overt Aggression Scale. They evaluated psychiatric symptoms through the Positive and Negative Syndrome Scale.

During the 12-week trial, patients with vs without a history of conduct disorder had more frequent and severe assaults. Clozapine was superior to both haloperidol and olanzapine in reducing assaults, and olanzapine was superior to haloperidol.

The greater antiaggressive efficacy of clozapine over haloperidol was more evident among patients with conduct disorder than those without. In patients with conduct disorder, clozapine was four times more likely to result in reduced violence compared to haloperidol. In those without conduct disorder, it was three times more likely to do so.

Likewise, olanzapine’s superiority over haloperidol was more evident in patients with conduct disorder.

“Treatment of violence in schizophrenia remains a challenging problem, especially in patients with conduct disorder,” the authors said. “Previous clinical studies did not select patients on the basis of violence and did not focus on conduct disorder.”