Nearly one-third of young adults diagnosed with attention deficit hyperactivity disorder (ADHD) go on to develop some form of substance abuse problem, according to a new study slated for the Journal of the American Academy of Child & Adolescent Psychiatry.
Investigators from Massachusetts General Hospital reviewed two long-term studies and found that ADHD alone significantly increases the risk of cigarette smoking and substance abuse in both boys and girls.
“Our study, which is one of the largest sets of longitudinal studies of this issue to date, supports the association between ADHD and substance abuse found in several earlier studies and shows that the increased risk cannot be accounted for by co-existing factors such as other psychiatric disorders or family history of substance abuse,” said researcher Timothy Wilens, M.D.
“Overall, study participants diagnosed with ADHD had a 1-1/2 times greater risk of developing substance abuse than did control participants.”
While previous studies suggested an increased risk of substance abuse in adolescents and young adults with attention deficit hyperactivity disorder , questions have been raised about whether specific aspects of ADHD were tied to substance abuse.
Researchers wondered if factors such as impulsive behavior, cognitive problems, school problems, accompanying conditions such as bipolar disorder or conduct disorder, or family factors were actually responsible for the risk.
To get a clearer picture of the factors behind the increased risk, the researchers examined data from two previous studies — one of boys, one of girls — that analyzed the prevalence of a broad range of psychiatric and behavioral disorders in participants diagnosed with attention deficit disorder as children.
From those two studies, a decade of more follow-up information was available for a total of 268 participants with ADHD and 220 control participants, both groups equally divided by gender.
Among the ADHD participants, 32 percent developed some type of substance abuse, including cigarette smoking, during the follow-up period, while only 25 percent of control participants had substance abuse problems.
Surprisingly, factors such as gender, cognitive difficulties, mood disorders, school problems or family history of substance abuse did not adversely impact the risk of developing a substance abuse problem.
The only additional diagnosis that had an effect was conduct disorder, which tripled the risk when combined with ADHD.
“Anyone with ADHD needs to be counseled about the risk for substance abuse, particularly if they have any delinquency,” said Wilens.
“We still need to understand why some kids with ADHD develop substance abuse and others don’t, whether particular treatment approaches can prevent substance problems and how best to treat young adults that have both ADHD and substance abuse.”