Antipsychotic Medication Is Effective in Treating Behavior Problems in Autistic Children, Yale-Based Study Shows

One of a newer class of antipsychotic medications was successful and well tolerated for the treatment of serious behavioral disturbances associated with autistic disorder in children ages 5-17, according to a Yale study published this week in the New England Journal of Medicine.

“Although our study did not attempt to treat the core symptoms of autism, our findings suggest that risperidone can be useful in treating moderate to severe behavior problems that are associated with autism in children,” said Lawrence Scahill, an associate professor at Yale School of Nursing and the Yale Child Study Center and lead author of the study.

The multi-site, eight-week, placebo-controlled clinical trial, titled “Risperidone in Children with Autism and Serious Behavioral Problems,” was funded by the National Institute of Mental Health (NIMH) and coordinated at Yale.

Autism is a serious chronic developmental disorder that appears in early childhood. It is characterized by profound impairments in the ability to relate to others, delayed language, and restricted patterns of behavior. It affects as many as 20 children per 10,000. Although causes of autism are unknown for most cases, available evidence implicates abnormalities in brain development. Twin and family studies indicate a strong genetic contribution.

In addition to core symptoms, children with autism frequently exhibit serious behavior disturbances, such as self-injury, aggression, and tantrums in response to routine environmental demands. For these disturbances, behavior therapy and medications are the two main forms of treatment.

Researchers randomly assigned 101 subjects, 82 males and 19 females, age 5 to 17, to receive either placebo or risperidone, one of the new atypical antipsychotics.

The study found risperidone to be significantly more effective than placebo in improving the serious behavioral problems in this group of children. Using a stringent definition of improvement, 69 percent of the children randomly assigned to risperidone showed a positive response compared with only 12 percent in the placebo group. No previous study in autism has shown this large treatment effect.

Risperidone was generally well tolerated. Of particular interest was the absence of neurological side effects, which are often seen with traditional antipsychotic medications. Risperidone was associated with an increase in body weight (an average of about 6-lb. increase in the 8-week period). This was a welcomed side effect for some children and a potential problem for others.

Several medications have been used previously to treat autism with limited success. To date, only haloperidol has been shown to be superior to placebo for serious behavior problems in more than one study. Concerns about neurological and other side effects of haloperidol cause many clinicians to avoid its use in children.

According to Scahill, atypical antipsychotics are of great interest in treating children with autism because studies have shown them to be beneficial to adults with schizophrenia, with fewer neurological side effects than older medications.

Few studies of atypical antipsychotics as treatments for children with autism have been published, but the medications are being used with increased frequency in clinics across the United States. The primary goal of this study was to evaluate the efficacy and safety of risperidone, the first widely available atypical, in children with autism accompanied by serious behavioral disturbance.

The study was conducted at five sites of the Research Units of Pediatric Psychopharmacology (RUPP) network, which is funded by NIMH. Research units at the University of California at Los Angeles, Ohio State University, Indiana University, Yale University, and the Kennedy Krieger Institute at Johns Hopkins University participated in the study.

“This is the largest randomized clinical trial in autism to date,” said Scahill. “It lays the groundwork for further research to help families better manage serious behavioral disturbance in children and adolescents with autism.”