Risperidone offers an effective, well-tolerated short-term treatment for tantrums and aggressive behavior in children with autistic disorders, report researchers in the New England Journal of Medicine.

The Research Units on Pediatric Psychopharmacology Autism Network conducted a multisite, double-blind trial of risperidone for the treatment of children with autistic disorders accompanied by tantrums, aggression, and self-injurious behavior.
In total, 101 children, aged 5–17 years old, were randomized to 8-weeks' treatment with risperidone (0.5–3.5 mg/day) or placebo.

Despite similar baseline clinical characteristics and mean scores on the Aberrant Behavior Checklist subscales, the children randomized to risperidone showed a significantly greater decrease in scores for the Irritability subscale than those assigned to placebo (56.9% vs 14.1%) after 8-weeks.

Moreover, 69.5% of the risperidone-treated children, compared with 12% of the placebo-treated children, achieved a "positive response", defined as a minimum of 25% improvement on the Irritability subscale alongside a rating of improved or much improved on the Clinical Global Impressions–Severity scale.

Analysis of secondary outcomes on the Aberrant Behavior Checklist also indicated risperidone significantly improved Stereotypy and Hyperactivity subscale scores. No significant difference was found for scales measuring Social Withdrawal and Inappropriate Speech.

Lead author Lawrence Scahill (Yale Child Study Center, New Haven, US) and colleagues note that no serious adverse events occurred, although the children assigned risperidone showed a significantly greater mean increase in weight, which was associated with mild or moderate increases in appetite.

Admitting the short trial length "limits inferences about adverse effects such as tardive dyskinesia," the team describes risperidone as "effective and well tolerated for the short-term treatment of tantrums, aggression, and self-injurious behavior in children with autistic disorder."