Stimulant Treatment Doesn't Appear to Raise Drug-Abuse Risk

Having attention-deficit/hyperactivity disorder in childhood may raise the risk of using alcohol or drugs in adolescence, but stimulant treatment does not appear to increase that risk.

Attention-deficit/hyperactivity disorder (ADHD) is associated with increased risk of illicit drug use. However, the slowly growing body of scientific literature on the topic shows mixed outcomes about the relationship between stimulant treatment and drug use, said Brooke Molina, Ph.D., an associate professor of psychiatry at the University of Pittsburgh, at the American Academy of Child and Adolescent Psychiatry (AACAP) annual meeting in New York in October.

“Some studies show protective effects of stimulants, some show predisposing effects, and some show no association at all,” said Molina. “This literature is still relatively new, and we cannot say if stimulant treatment protects against later drug abuse.”

These studies also have problems, including a large range of sample sizes, different age ranges at follow-up, and varying ways that treatment and outcomes were operationalized, she pointed out.

Molina began her career by studying children of alcoholics and noticed that their symptoms overlapped with those of children with ADHD. In addition, core symptoms of ADHD, such as inattention, impulsivity, hyperactivity, and restlessness, are also implicated in addiction.

“There are also similarities in brain areas implicated and in genetic vulnerabilities,” she said. “In ADHD, we need to think about both impairments and symptoms.”

At the AACAP meeting, Molina reported on eight-year outcomes of the association between ADHD treatment and substance use from the NIMH-sponsored Multimodal Treatment Study of Children With ADHD (MTA).

The MTA was a large, multisite, randomized treatment trial of 436 patients with a narrow age range (7 to 9.9 years at baseline).

The initial MTA trial randomly assigned patients to one of four treatment conditions: medication only, behavioral treatment only, combined medication and behavioral, or assessment and referral.

Molina studied risk for substance use among these children in the years after the formal end of treatment. Treatment didn't appear to have much effect on rates of substance use, which were fairly high in both the ADHD and control groups. At the two-year follow-up, the two groups receiving behavioral therapy showed slight protective effects, but that disappeared at three years, she said.

“By eight years, there was no visible harm, but no protective effect either,” said Molina. “Use of behavioral therapies was associated with reduced substance use or experimentation in early adolescence. We'll have more information at 12 years, but adolescent substance abuse appears to be episodic and socially mediated.”

Early ADHD symptom patterns were the most predictive, regardless of treatment type.