Weight Gain With Risperidone Among Patients With Mental Retardation: Effect of Calorie Restriction

Background: The atypical antipsychotics causeweight gain, which is poorly understood in terms of its mechanismand treatment. A usual recommendation for treatment ofantipsychotic-induced weight gain includes calorie restrictionand exercise. The authors describe their recent clinicalexperience with calorie restriction in adults with mentalretardation treated with risperidone.

Method: A retrospective chart review wasperformed on the records of 50 adult patients with mentalretardation treated with risperidone while residing at ahabilitation center. We assessed dose and duration of risperidonetreatment, weight, changes in calorie intake, and frequency ofaggressive behavior.

Results: Of the 50 patients, 39 had adequatedata for analysis. Thirty-seven of the 39 patients gained weightwith a mean of 18.8 lb (8.3 kg) over about 2 years. Twenty of the37 patients were calorie restricted. Three of the 20calorie-restricted patients lost weight at a rate of 0.2 lb (0.1kg) per month. The other 17 calorie-restricted patients and the17 patients who were not calorie restricted continued to gainweight at a rate of 0.8 lb (0.4 kg) per month over about another2 years of treatment. The amount of weight gain was not doserelated. Calorie restriction led to no deterioration in behavior.

Conclusion: The current investigation lendssupport to data that note weight gain with risperidone in adultswith mental retardation. It suggests that calorie restrictiondoes not lead to weight loss or behavioral deterioration and thatweight gain is not dose related.