ABSTRACT
The authors report five cases of very young children with autistic disorder, aged 2.1-3.7 years, treated with risperidone, as part of the comprehensive intervention. Treatment with risperidone 0.25-0.5 mg per day was associated with clinically meaningful decreases in problem behaviors including hyperactivity, irritability, and aggressiveness. There were also improvements in social relatedness and cooperation with developmental treatment. All of the children tolerated the medication well and experienced no untoward effects. The efficacy of risperidone in the treatment of very young children with autistic disorder reported here is consistent with findings in the limited number of cases previously reported in the literature. Controlled studies are needed to confirm the efficacy and safety of risperidone in the treatment of these children.