Methylphenidate may be effective in treating autism

Methylphenidate, a medication used to treat attention-deficit hyperactivity disorder (ADHD), may be effective in treating hyperactivity symptoms in children with autism and related pervasive developmental disorders, researchers report in the November Archives of General Psychiatry.

The study was conducted by the Research Units on Pediatric Psychopharmacology (RUPP) Autism Network, a National Institute of Mental Health funded multi-site consortium dedicated to the development and testing of treatments for children with pervasive developmental disorders such as autism. The Yale team is directed by Lawrence Scahill, associate professor of nursing and child psychiatry at Yale.

"This study shows that methylphenidate is an effective medication for children with pervasive developmental disorder (PDD) accompanied by increased hyperactivity," said Scahill. "However, the percentage of children showing a positive response and the magnitude of benefit is lower than what we have come to expect in ADHD uncomplicated by PDD."

"Although the adverse effects that we observed in this study are similar to what we see in typically developing children with ADHD, these adverse effects occurred at a much higher frequency in our study subjects, " Scahill added.

RUPP investigators conducted a randomized, placebo-controlled trial to determine whether methylphenidate would be effective in reducing hyperactivity in children with PDD. The trial included a one-week test phase to ensure that subjects could tolerate three different dose levels of the medication, followed by a four-week (crossover) phase in which children were given one of three doses of methylphenidate or placebo to assess effectiveness. Parents, teachers and investigators, who rated the child's behavior, were blind to the child's drug dose. Children showing a positive response to any dose during the crossover phase were treated for an additional eight-week period to ensure the gains were stable.

The study evaluated 72 children between the ages of five and 14. Of the 58 participants who completed the crossover phase, 35 responded best to an active dose of methylphenidate and the drug was consistently more effective than placebo on measures of inattention, hyperactivity and impulsivity rated by parents and teachers.