January 17, 2003

An analysis of all studies that examine the impact of stimulant treatment for attention-deficit hyperactivity disorder (ADHD) on future substance abuse supports the safety of stimulant treatment. Using a statistical technique called meta-analysis, the MGH researchers found that medication treatment for children with ADHD resulted in an almost two-fold reduction in the risk of future substance abuse. The report appears in the January issue of Pediatrics.

"We know that untreated individuals with ADHD are at a significantly increased risk for substance abuse. And we understand why parents often ask whether stimulant medications might lead to future substance abuse among their children," says Timothy Wilens, MD, the paper's lead author and MGH director of Substance Abuse Services in Pediatric Psychopharmacology. "Now we can reassure parents and other practitioners that treating ADHD actually protects children against alcohol and drug abuse as well as other future problems."

Wilens and his MGH colleagues have conducted previous studies that found a protective effect in stimulant treatment. At least one report from another research center, however, asserted that stimulant treatment increased the risk of later substance abuse. In order to resolve the question, the team searched the medical literature for ADHD studies that included followup information on later substance abuse. They identified six such studies conducted in the United States and Germany, including both the previous MGH research and the study suggesting increased risk.

After application of standard meta-analysis techniques, the researchers found a significant overall reduction in the risk of subsequent substance abuse among those receiving stimulant treatment. They note that four of the six studies showed "striking protective effects of stimulant medications." The research team — which also includes Stephen Farone, PhD, Joseph Biederman, MD, and Samantha Gunawardene — is continuing to study the biological and psychological mechanisms by which ADHD increases the risk for substance abuse in young people and why treatment decreases the ultimate risk.