Risperidone use in autism spectrum disorders: a retrospective review of a clinic-referred patient population.

Risperidone is widely used in children with autism spectrum disorders for behavioral modification. In this study, the authors aimed to (1) describe a clinic-referred sample of patients with an autism spectrum disorder on risperidone, (2) identify differences between the success and nonsuccess groups, and (3) describe our experience with young children (< age 5 years) on risperidone. Eighty patients were initiated on risperidone. Indications included aggression (66%), impulsivity (14%), and stereotypies (4%). Sixty-six percent met criteria for success at 6 months and 53% at 1 year. Sixty-seven percent of the nonsuccess group reported side effects, compared to 47% of the success group. Weight gain was the most common side effect in both groups, followed by somnolence. Somnolence was the most robust predictor of nonsuccess. In our clinic-referred sample, the short-term success rate of risperidone was more than 50%, and side effects limited its use. Although weight gain was common, somnolence more significantly influenced treatment discontinuation.