Autism is a potentially devastating developmental disorder. In addition to its core symptoms—impaired social skills, verbal communication, and cognitive and behavioral flexibility—some autistic children exhibit serious behavioral disturbances, such as tantrums, aggression, and self-inflicted injuries. Research published in the July 31, 2002 issue of The New England Journal of Medicine suggests that the antipsychotic drug risperidone (Risperdal) may improve behavior in children with autism who exhibit severe behavioral problems.

About the study

Researchers from the Autism Network of the Research Units on Pediatric Pharmacology studied 101 boys and girls with autism and serious behavioral problems. The children were between the ages of 5 and 17 years and were free of any serious medical conditions or other psychiatric disorders. Autistic children taking medication deemed to be effective for severe behavioral disturbances were excluded from the study.

At the start of the study, children underwent testing for autism (via an interview with a physician), intelligence tests, routine laboratory tests, and a physical exam. Parents were asked about their children’s medical history and asked to rate their behavior on the Irritability subscale of the Aberrant Behavior Checklist. In addition, a physician rated the child’s behavior using the Clinical Global Impressions – Severity (CGI-S) scale.

The children were randomly assigned to take either risperidone or a placebo (inactive) pill twice daily for 8 weeks. At weekly doctor visits, the children were assessed for changes in vital signs, height, weight, general health, energy level, appetite, muscle stiffness, motor restlessness, bowel and bladder habits, and sleep habits. After the 8 weeks, both groups were given the opportunity to take risperidone for 4 months.

At the end of the study, researchers compared the behavior of children taking risperidone with the behavior of those taking placebo, again using the Irritability and CGI scales.

The findings

Sixty-nine percent of children taking risperidone experienced improvement in behavior compared with only 12% of children taking placebo. For the purposes of this study, improvement was defined as a minimum 25% decrease in the Irritability score combined with a rating of “much improved” or “very much improved” on the CGI – Improvement scale. In addition, these improvements in behavior were maintained after 6 months.

Increased appetite, fatigue, drowsiness, dizziness, and drooling were more common in the risperidone group than in the placebo group. However, most of these side effects subsided within a few weeks. On average, children taking risperidone gained slightly more weight during the eight weeks than children taking placebo.

Although this research suggests that risperidone can relieve behavioral problems sometimes associated with autism, this study has its limitations. First, the relatively short study period precludes assessment of longer-term side effects of risperidone. Second, only autistic children were included in this study, so it’s unclear whether risperidone will be helpful for children with other pervasive developmental disorders. Third, this study measured changes in behavioral symptoms associated with autism, but not the core symptoms of autism. Finally, more research is needed on how risperidone compares with behavior therapy and the effectiveness of risperidone and behavior therapy combined.

How does this affect you?

This study suggests that risperidone may help reduce tantrums, aggression, and self-injurious behavior in some autistic children. It’s important to understand, though, that risperidone was not tested as a treatment for the core symptoms of autism—impaired social skills, verbal communication, and cognitive and behavioral flexibility.

If your child has autism with serious behavioral problems, ask your health care provider about the possibility of trying risperidone.