The effect of long-term antipsychotic treatment on the body weight of patients suffering from chronic schizophrenia: clozapine versus classical antipsychotic agents

The aim of this study was to evaluate the effect of long-term clozapine treatment on body weight changes in neuroleptic-resistant chronic schizophrenic patients and to compare it with that of classical antipsychotic agents. The body mass index (BMI) of 96 neuroleptic-resistant chronic schizophrenic patients was calculated before the beginning and after long-term (mean +/- SD 1.7 +/- 1.3 years) clozapine treatment. These data were compared to the BMI of 98 chronic schizophrenic patients maintained on classical antipsychotic agents for a similar duration (mean +/- SD 1.9 +/- 1.6 years). A significant elevation in BMI was detected in both groups during these periods (P0.0001 versus baseline, for both groups). The change in BMI (delta BMI) was similar in both groups (P0.9). We conclude that the increase in body weight caused by long-term (6 months) clozapine treatment is comparable to that obtained following long-term classical antipsychotic agents treatment.