Children with autism marked by tantrums, aggression, and/or self-injury had a decrease in behaviors during six months of therapy with risperidone, although behaviors returned quickly in most patients after drug discontinuation, according to an article in the July issue of the American Journal of Psychiatry.

“A variety of treatments, including medication, are used to manage aggressive behaviors in autistic children, but controlled medication trials are limited,” said Dr. James McCracken, lead author and site investigator at the Semel Institute for Neuroscience and Human Behavior at University of California Los Angeles. “Our findings support adding risperidone to the small arsenal of intermediate-term medication options for the tens of thousands of children with autism who display aggressive and destructive behaviors.

“The response to risperidone ranks among the most positive ever observed in children with autism for a drug treatment,” said McCracken.

Autism affects as many as 20 in 10,000 children. In addition to core symptoms, children with autism frequently exhibit serious behavior disturbances in response to routine environmental demands. For these disturbances, behavior therapy and medications are the two main forms of treatment.

In the multi-site study, researchers randomized 101 subjects - 82 boys and 19 girls - ages 5 to 17 years to placebo or risperidone. Subjects who improved substantially after 8 weeks continued treatment for up to 6 months. Researchers observed a small sample of subjects at the end of the study during withdrawal of medication.

Previously, the largest extended studies of medication for autism with haloperidol, an older antipsychotic, showed the drug to be modestly effective but accompanied by neurological and other side effects.

Past research into risperidone for children with autism found the medication effective for short-term treatment of aggressive behaviors related to autism. Risperidone was usually well-tolerated, with some complaints of weight gain.

The intermediate-term risperidone study was conducted at five sites of the Research Units of Pediatric Psychopharmacology (RUPP) network, which is funded by the National Institutes of Mental Health. The RUPP network is composed of research units devoted to conducting studies to test the efficacy and safety of medications commonly used off-label to treat children and adolescents.

In clinical practice, many medications are used in the treatment of autism, but few medications have been carefully studied to determine the safety and effectiveness of the medication for the treatment of childhood illnesses.