Differential Effect of Clozapine on Weight

A Controlled Study

Bustillo, Juan R. MD
Buchanan, Robert W. MD
Irish, Donna RN
Breier, Alan MD

Received Aug. 29, 1995; revision received Jan. 24, 1996; accepted Feb. 2, 1996. From the Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine. Address reprint requests to Dr. Bustillo, Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228.
Supported in part by grants from the National Research Service Award Program for Minority Research Training in Psychiatry and NIMH grant MH-45074.

American Journal of Psychiatry 153(6):p 817-819, June 1996.

Objective

This study examined whether clozapine induces more weight gain than haloperidol and whether weight gain is related to clinical improvement. Method: The weight and symptoms of 39 outpatients with schizophrenia who were randomly assigned to double-blind treatment with either clozapine or haloperidol were assessed. The weight and symptoms of 33 of the patients who chose to take clozapine during a 1-year follow-up after the study ended were also assessed. Results: The patients treated with clozapine gained significantly more weight over baseline (7%) than the haloperidol-treated patients (1%). Weight gain was not significantly correlated with improvements in either positive or negative symptoms. Fiftyeight percent of the patients followed for 1 year gained at least 10% over their baseline weight. Conclusions: Weight gain is an important side effect of clozapine and is unrelated to the drug's differential antipsychotic efficacy.

(Am J Psychiatry 1996; 153:817-819)