ADHD Treatment and Subsequent Substance Abuse

Attention deficit hyperactivity disorder (ADHD) affects about one in 30 young people. Pharmacological treatments include several types of stimulants, which have the potential to be abused, and substance use disorders are more common in young people with ADHD than those without ADHD. Whether individuals treated with stimulants are at increased risk for developing problems with recreational drugs has been a subject for research, but results so far have been inconclusive.

Large-scale health-records data provide a valuable resource to study this question. A group of investigators using data from Swedish health registries found that people treated with stimulants for ADHD were not at increased risk for substance abuse. In fact, they may have had lower rates of substance abuse than individuals with ADHD who were not treated.

Patrick Quinn and colleagues have also addressed this question using health claims data from a very large U.S. database. The results of their study were published in the American Journal of Psychiatry.

Quinn and colleagues identified almost 3 million individuals who were either diagnosed with ADHD or received treatment with ADHD medications between 2005 and 2014. They examined data for patients who were 13 years old and older because substance use is rare in younger individuals. The sample was fairly evenly divided between males (53 percent) and females (47 percent). The median age for the males was 21 and, for the females, 28. The investigators reviewed ADHD medication usage and claims for emergency room visits with any non-tobacco-related substance use disorder diagnosis over the length of the study period. They defined such emergency room visits as substance-related events.

Quinn’s group found that individuals with ADHD had more substance-related events than those without ADHD (about 3 percent vs. 1 percent). However, individuals who had taken ADHD medications were less likely to have had substance-related events than those who had not taken medications.

One advantage of the longitudinal nature of this study was that the investigators could follow each patient’s record individually and make “within individual” comparisons. Thus, they were able to discern whether an individual was on or off ADHD medication at the time of a particular emergency room visit. When they analyzed the data this way, they found that males had 35 percent lower odds of substance-use-related emergency room visits and females 31 percent lower odds of such emergency room visits during times when they were being treated with ADHD medications.

Most individuals being treated for ADHD with medications are taking stimulants. Although it may seem counterintuitive, the use of stimulants, which can be abused, appears to be associated with an actual decrease in the problematic use of recreational drugs in those with ADHD. Why this happens was not addressed in this study. It is possible that improvement in ADHD symptoms resulting from stimulant use helps young adults avoid problematic recreational drug use. Also, treatment with stimulants may influence the brains of young adults with ADHD differently than the brains of those without ADHD.

Whatever the reason, these data demonstrating a decrease in substance use problems as a result of treatment with stimulants in persons with ADHD are reassuring, although the use of emergency room visits as a proxy for substance use problems is a significant limitation in interpreting and generalizing the results.

This post was written by Eugene Rubin MD, PhD and Charles Zorumski MD.