The antipsychotic drug Risperdal decreased tantrums, aggression and self-injurious behavior among children with autism in a small study funded by the government.

This is the first time that any drug from a relatively new class of medications called atypical antipsychotics has been systematically studied in autistic children.

“The response to [Risperdal] ranks among the most positive ever observed in children with autism for a drug treatment,” said study investigator James McCracken, a professor of psychiatry and biobehavioral sciences at the University of California at Los Angeles. The study was published last week in the American Journal of Psychiatry.

But the drug was not superior to a placebo in improving language skills and social relatedness – two problems symptomatic of the disorder – among autistic children. Researchers found some signals, however, that the drug might help with their social deficits, perhaps because reducing tantrums and aggressive behavior allowed the children “to be more available for social interaction.”

The drug was also superior to placebos in reducing repetitive behaviors – another hallmark of autism – among the children.