A double-blind, placebo-controlled study of risperidone in adults with autistic disorder and other pervasive developmental disorders. Risperidone in children with autism and serious behavioral problems.
Neurobiological research has implicated the dopamine and serotonin systems in the pathogenesis of autism. Open-label reports suggest that the serotonin2A-dopamine D2 antagonist risperidone may be safe and effective in reducing the interfering symptoms of patients with autism.
                Thirty-one adults (age [mean+/-SD], 28.1+/-7.3 years) with autistic disorder (n=17) or pervasive developmental disorder not otherwise specified (n=14) participated in a 12-week double-blind, placebo-controlled trial of risperidone. Patients treated with placebo subsequently received a 12-week open-label trial of risperidone.
                For persons completing the study, 8 (57%) of 14 patients treated with risperidone were categorized as responders (daily dose [mean+/-SD], 2.9+/-1.4 mg) compared with none of 16 in the placebo group (P<.002). Risperidone was superior to placebo in reducing repetitive behavior (P<.001), aggression (P<.001), anxiety or nervousness (P<.02), depression (P<.03), irritability (P<.01), and the overall behavioral symptoms of autism (P<.02). Objective, measurable change in social behavior and language did not occur. Nine (60%) of 15 patients who received treatment with open-label risperidone following the double-blind placebo phase responded. Other than mild, transient sedation, risperidone was well tolerated, with no evidence of extrapyramidal effects, cardiac events, or seizures.
                Risperidone is more effective than placebo in the short-term treatment of symptoms of autism in adults. Atypical antipsychotic agents, which block postsynaptic dopamine and serotonin receptors, have advantages over traditional antipsychotic medications in the treatment of adults with schizophrenia and may be beneficial in children with autistic disorder who have serious behavioral disturbances. However, data on the safety and efficacy of atypical antipsychotic agents in children are limited.
                We conducted a multisite, randomized, double-blind trial of risperidone as compared with placebo for the treatment of autistic disorder accompanied by severe tantrums, aggression, or self-injurious behavior in children 5 to 17 years old. The primary outcome measures were the score on the Irritability subscale of the Aberrant Behavior Checklist and the rating on the Clinical Global Impressions - Improvement (CGI-I) scale at eight weeks.
                A total of 101 children (82 boys and 19 girls; mean [+/-SD] age, 8.8+/-2.7 years) were randomly assigned to receive risperidone (49 children) or placebo (52). Treatment with risperidone for eight weeks (dose range, 0.5 to 3.5 mg per day) resulted in a 56.9 percent reduction in the Irritability score, as compared with a 14.1 percent decrease in the placebo group (P<0.001). The rate of a positive response, defined as at least a 25 percent decrease in the Irritability score and a rating of much improved or very much improved on the CGI-I scale, was 69 percent in the risperidone group (34 of 49 children had a positive response) and 12 percent in the placebo group (6 of 52, P<0.001). Risperidone therapy was associated with an average weight gain of 2.7+/-2.9 kg, as compared with 0.8+/-2.2 kg with placebo (P<0.001). Increased appetite, fatigue, drowsiness, dizziness, and drooling were more common in the risperidone group than in the placebo group (P<0.05 for each comparison). In two thirds of the children with a positive response to risperidone at eight weeks (23 of 34), the benefit was maintained at six months.
                Risperidone was effective and well tolerated for the treatment of tantrums, aggression, or self-injurious behavior in children with autistic disorder. The short period of this trial limits inferences about adverse effects such as tardive dyskinesia.
                Copyright 2002 Massachusetts Medical Society
Risperidone can be beneficial in some features of autism. However there are limited data available from studies with small sample sizes. In addition, there lacks a single standardised outcome measure allowing adequate comparison of studies, and long-term followup is also lacking. Further research is necessary to determine the efficacy pf risperidone in clinical practice.