Risperidone, an antipsychotic drug, has proven effective for the treatment of behavioral problems in autistic children, according to a Yale study published in July in The New England Journal of Medicine. The clinical trial targeted not the core symptoms of autism, including impaired relations with others and delayed language, but related problems such as self-injury, aggression and tantrums, said Lawrence D. Scahill, M.S.N., M.P.H. ’89, Ph.D. ’97, an associate professor at the Yale Child Study Center and lead author of the study. More than two-thirds of the children randomly assigned to risperidone showed a positive response, compared with 12 percent in the placebo group. No previous study on autism has shown this large a treatment effect.