Ritalin May Ease Hyperactivity In Autism-Related Disorders

Ritalin (methylphenidate), long an approach to attention deficit hyperactivity disorder (ADHD) in children, may be effective for treating hyperactivity in autism and related pervasive developmental disorders, according to investigators here.

Nearly 50% of children with pervasive developmental disorders and hyperactivity responded to the drug, but the magnitude of the response was less than that seen with children with ADHD, reported investigator David J. Posey, M.D., of the Indiana University School of Medicine here, and colleagues in the November issue of Archives of General Psychiatry.

Seventy-two children, ages five to 14 years, participated in the randomized, placebo-controlled, crossover trial. The trial included a one-week phase to test whether the participants could tolerate three different dose levels of the medication. This was followed by a four-week crossover phase during which the children were given one of three doses of Ritalin or placebo in random order to assess effectiveness.

Children showing a positive response were treated for an additional eight weeks to ensure that gains were stable. Response to treatment was assessed by parents and teachers using standardized ratings of behavior.

Thirty-five children (49%) responded to the drug, which is less than response rates of 70% to 80% reported for children with ADHD. Responders were defined as those who showed at least a 25% decrease in hyperactivity symptoms. Some children showed as much as a 54% decrease in symptoms. The effect sizes ranged from 0.20 to 0.54, suggesting a small to medium magnitude of response.

The drug did not improve symptoms of irritability, lethargy, social withdrawal, stereotypy, or inappropriate speech. Increased social withdrawal was associated with higher doses of the medication, which is consistent with adverse events reported in other studies.

Overall, 18% of the children withdrew from the study because of adverse events, most commonly irritability. Other adverse events at the highest dose included appetite decrease (24%), difficulty falling asleep (16%), and stomach or abdominal discomfort (12%).

“At present, methylphenidate is a reasonable choice to target hyperactivity in the context of pervasive developmental disorders, given modest group effects and a response rate that approaches 50%,” the study authors concluded.

“However, caregivers should be cautioned about the strong possibility of adverse effects. In addition, practitioners should be prepared to suspend treatment if considerable adverse effects are reported,” they added.

The authors also raised the possibility that “the use of psychostimulants added to another psychotropic medication may be associated with a greater rate of response than when used alone. For example, persons with autism already receiving an antipsychotic medication might be protected to some extent from adverse effects associated with psychostimulants (e.g., irritability, insomnia, loss of appetite).”

Ritalin is also sold under the brand names Concerta, Metadate, and Methylin. The study was not supported by any of the drug-makers.

Source: Archives of General Psychiatry

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