Methylphenidate shows promise for hyperactivity associated with autism

Nov 7 2005

Medication commonly used to treat attention-deficit hyperactivity disorder (ADHD) may be effective for treatment of hyperactivity symptoms in children with autism and related pervasive developmental disorders, according to a study in the November issue of Archives of General Psychiatry.

Children with autism and other pervasive developmental disorders often also have symptoms of hyperactivity, distractibility and impulsiveness requiring treatment, according to background information in the article. Some previous small studies on the use of medications to treat hyperactivity in these children have shown promise, although side effects have been common, including irritability and social withdrawal.

David J. Posey, M.D., Indiana University School of Medicine, Indianapolis, and colleagues in the Research Units on Pediatric Psychopharmacology (RUPP) Autism Network conducted this study. The RUPP Autism Network is funded by the National Institute of Mental Health and is dedicated to the development and testing of treatments for children with autism and related conditions. In this study the investigators conducted a randomized, placebo-controlled crossover trial to determine whether methylphenidate (a medication commonly used in the treatment of ADHD) would be effective in reducing hyperactivity and impulsiveness in children with pervasive developmental disorders. 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 methylphenidate or placebo in random order to assess effectiveness. Children showing a positive response were treated for an additional eight-week period to ensure that gains were stable. Response to treatment was assessed by parents and teachers using standardized ratings of behavior.

Seventy-two children, aged five to 14 years participated in the study. Six participants (eight percent) had intolerable negative side effects with more than one dosage level and withdrew from the study. Sixteen of the remaining children had intolerable negative side effects at the highest dose and were randomized to a modified crossover phase that omitted the highest dose. Seven participants withdrew due to intolerable negative side effects during the crossover phase, three at the highest dose, three at the medium dose and one while receiving the lowest dose. One child withdrew from the study for unspecified reasons, 58 children completed the crossover phase of the study.

Forty-four (76 percent) of the 58 participants responded during at least one of the four treatment conditions, the researchers report. Methylphenidate was consistently more effective in improving inattention, distractibility, hyperactivity and impulsivity than placebo.

"At present, methylphenidate is a reasonable choice to target hyperactivity in the context of PDDs [pervasive developmental disorders], given modest group effects and a response rate that approaches 50 percent," the authors conclude. "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. Further secondary analyses are planned to better delineate individual responses and other moderators of response, including genotype."