Antipsychotic Drug Risperidone Reduces Tics in Children and Adults with Tourette Syndrome
“These results suggest that risperidone is safe and effective for short-term treatment of tics in children or adults with Tourette syndrome,” said lead author Lawrence Scahill, associate professor in the Yale School of Nursing and the Yale Child Study Center. “Longer-term studies are needed to evaluate the durability of efficacy and safety over time.”
Published in the current issue of Neurology, the study looked at 34 patients (26 children and eight adults) who were randomly assigned to receive either risperidone or a placebo for eight weeks. The medication or a placebo was administered on a gradually increasing dose to minimize side effects over the first four weeks of the study. Patients were seen every other week to evaluate response and adjust the dose. The primary outcome measure was based on patient and family interviews by a clinician who was blind to the treatment assignment.
After eight weeks of treatment, the 16 subjects on risperidone showed a 32 percent reduction in tic severity. The placebo group showed only a seven percent reduction. Scahill said this difference was statistically and clinically significant. Similar results were observed when the children were evaluated separately. The 12 children randomized to risperidone showed a 36 percent reduction in tic symptoms compared to an 11 percent decrease in the 14 children on placebo. The medication was generally well tolerated.
“Of particular note is that there were no neurological side effects such as dystonia, dyskinesia or restlessness, which are often seen in the traditional antipsychotic medications that are commonly used for the treatment of tics in TS,” said Scahill.
Symptoms of Tourette syndrome include persistent motor and phonic tics affecting one to eight per 1,000 school-age children. The tics include jerking movements of the body and involuntary vocalizations. Common motor tics include eye blinking, facial movements, head jerking or shrugging. Common vocal tics include grunting, coughing, throat clearing or snorting. In many cases the tics are mild and may not require treatment with medication. When tics occur frequently, in combinations or involve more disruptive movements or sounds, medication is prescribed. Until recently, few new medications were available for the treatment of tics.
Risperidone, which was developed for the treatment of adults with schizophrenia, was introduced in 1994. This study was the second to compare risperidone and placebo in a randomized clinical trial.
Collaborators on the study included Yale Child Study Center researchers James Leckman, Robert Schultz, Lily Katsovich and Bradley Peterson, who is now at Columbia University.
The study was funded in part by the following organizations: the Tourette Syndrome Program Project and the Research Units on Pediatric Psychopharmacology of the National Institutes of Health; the Children’s Clinical Research Center and Janssen Pharmaceutica Products, LP.