The atypical antipsychotic agent risperidone is successful and well
tolerated as treatment for serious behavioral disturbances associated
with autism in children ages 5 to 17 years, according to an article
in the August 1st issue of the New England Journal of Medicine. The
findings emerged from an eight-week, placebo-controlled clinical trial
involving 101 American children.
"Although this study did not attempt to treat the core symptoms
of autism, our findings suggest that risperidone can be useful in
treating moderate to severe behavior problems that are associated
with autism in children," said Lawrence Scahill, Ph.D., principal
investigator at one hospital in the multi-site trial.
Autism affects as many as 20 children per 10,000. Although its
causes are largely unknown, available evidence implicates abnormalities
in brain development and a strong genetic contribution. In addition
to core symptoms, children with autism frequently exhibit serious
behavioral disturbances such as self-injury, aggression, hyperactivity,
and tantrums in response to routine environmental demands. For these
disturbances, behavioral therapy and medications are the two main
forms of treatment.
In the current, multi-site study, researchers randomly assigned
101 children and
adolescents, 82 boys and 19 girls, age 5 to 17 years, to receive
either placebo or
risperidone.
Investigators found risperidone to be significantly more effective
than placebo
in improving behavior. Using a stringent definition of improvement,
69 percent of the children randomly assigned to risperidone were
much or very much improved at the end of the eight-week study compared
with only 12 percent in the placebo group. This is the largest positive
effect by a medication ever observed in children with autism.
Risperidone was well tolerated, with few neurological side effects.
However,
drug use was associated with a substantial increase in body weight
(an
average of about a six-pound increase in the eight-week period).
Several medications have been used to treat autism previously but
with limited
success. To date, only haloperidol has been shown to be superior
to placebo for serious behavior problems in more than one placebo-controlled
study. Concerns about neurological and other side effects of haloperidol
cause many clinicians to avoid its use in children.
Few studies of atypical antipsychotic medications have been conducted
in children with autism. The primary goal of the current work was
to evaluate the efficacy and safety of risperidone, the first widely
available atypical antipsychotic agent, in this pediatric population.