People with attention deficit hyperactivity disorder or ADHD have difficulties with inattention, hyperactivity and impulsivity. ADHD is typically diagnosed in childhood, but the symptoms can last into adulthood.
ADHD is treated with home, school and workplace accommodations, a variety of therapies, and with medications, the most common of which are stimulants such as Ritalin, Adderall, dexedrine, Concerta, methylphenidate; and a non-stimulant medication called atomoxetine (Strattera).
Because children with ADHD so often take prescription stimulants to improve their attention, there has been concern that they might be more at risk for substance use and abuse as they grow older. Some early studies provided evidence for this possibility.
When the ADHD patients took their medications, they were less likely to have substance-related events.
The investigators used data from health records of almost three million patients, 13 years old and up, collected from 2005-2014. They compared patients with ADHD who were treated with stimulants or with atomoxetine to those who weren't. They also looked at whether the substance use of patients who were treated with medications changed when they were on or went off their medications. Finally, they examined both concurrent substance use and the long-term risk of substance use even after treatment had ended.
The data revealed that among the patients with ADHD, males who had been treated with medication were less likely than their untreated male peers with ADHD to have substance-related events. This was also seen, though less dramatically, in the female patients who were treated with medication.
The odds of substance-related events were 19 percent lower among male patients and 11 percent lower among female patients during medicated months than during the same patients' unmedicated months. When the ADHD patients took their medications, they were less likely to have substance-related events. Over the long term, the use of ADHD medication predicted a 19 percent reduction in substance-related events two years later among male patients, and a 14 percent reduction among female patients. This positive effect has been seen to decrease with more time.
The authors conclude that there is almost no evidence that medication to treat ADHD increases the risk of substance-related events, even among those with pre-existing substance use disorders.
ADHD medications should not be used as first line treatments for substance abuse disorders in the absence of an ADHD diagnosis, but these findings suggest that ADHD medications do not increase the risk of substance use and that they may, in fact, be somewhat protective. They should be taken into account when patients and health care providers are making treatment decisions for ADHD therapy.
The study is published in the American Journal of Psychiatry.