A placebo-controlled trial of risperidone in Tourette syndrome

Objective: To evaluate the efficacy and safety of risperidone in children and adults with Tourette syndrome. Methods: This was an 8-week, randomized, double-blind, placebo-controlled trial. The primary outcome measure was the Total Tic score of the Yale Global Tic Severity Scale (YGTSS). Results: Thirty-four medication-free subjects (26 children and 8 adults) ranging in age from 6 to 62 years (mean = 19.7 +/- 17.0 years) participated. YGTSS Total Tic scores were similar at baseline (26.0 +/- 5.1 for risperidone vs 27.4 +/- 8.5 for placebo). After 8 weeks of treatment (mean daily dose of 2.5 +/- 0.85), the 16 subjects on risperidone showed a 32% reduction in tic severity from baseline, compared to a 7% reduction for placebo patients (n = 18) (F[2,64] = 6.07; p = 0.004). The 12 children randomized to risperidone showed a 36% reduction in tic symptoms compared to an 11% decrease in the 14 children on placebo (F [2,48] = 6.38; p = 0.004). Two children on risperidone showed acute social phobia, which resolved with dose reduction in one subject but resulted in medication discontinuation in the other. A mean increase in body weight of 2.8 kg was observed in the risperidone group compared to no change in placebo (F[2,64] = 10.68; p = 0.0001). No extrapyramidal symptoms and no clinically significant alterations in cardiac conduction times or laboratory measures were observed. Conclusion: Risperidone appears to be safe and effective for short-term treatment of ties in children or adults with Tourette syndrome. Longer-term studies are needed to evaluate the durability of efficacy and safety over time.