A double-blind, placebo-controlled study of risperidone in adults with autistic disorder and other pervasive developmental disorders

Arch Gen Psychiatry. 1998 Jul;55(7):633-41. doi: 10.1001/archpsyc.55.7.633.


Background: 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.

Methods: 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.

Results: 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.

Conclusion: Risperidone is more effective than placebo in the short-term treatment of symptoms of autism in adults.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aggression / drug effects
  • Aggression / psychology
  • Antipsychotic Agents / adverse effects
  • Antipsychotic Agents / therapeutic use*
  • Autistic Disorder / diagnosis
  • Autistic Disorder / drug therapy*
  • Autistic Disorder / psychology
  • Child Development Disorders, Pervasive / diagnosis
  • Child Development Disorders, Pervasive / drug therapy*
  • Child Development Disorders, Pervasive / psychology
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Placebos
  • Psychiatric Status Rating Scales
  • Risperidone / adverse effects
  • Risperidone / therapeutic use*
  • Severity of Illness Index
  • Treatment Outcome
  • Weight Gain / drug effects


  • Antipsychotic Agents
  • Placebos
  • Risperidone