Lack of efficacy of clozapine monotherapy in refractory obsessive- compulsive disorder

OBJECTIVE: The authors assessed the efficacy of clozapine monotherapy for adults with treatment-resistant obsessive-compulsive disorder. METHOD: Twelve adults with refractory obsessive-compulsive disorder participated in a 10-week, open-label, systematic trial of clozapine. They were assessed with the Yale-Brown Obsessive Compulsive Scale, the Hamilton Depression Rating Scale, and the global improvement item of the Clinical Global Impression (CGI) scale. RESULTS: None of the 10 patients who completed the trial was a responder. No significant change was observed in obsessive-compulsive or depressive symptoms or in scores on the CGI global improvement item. CONCLUSIONS: These findings suggest that clozapine monotherapy is not effective for most adult patients with treatment-resistant obsessive-compulsive disorder.