ADHD Risk Factor for Smoking, Substance Abuse
Children and adolescents who have ADHD (attention deficit/hyperactivity disorder) are more likely to adopt smoking habits and engage in substance abuse than are young people without the disorder. This finding comes from an analysis of two long-term studies by investigators at Massachusetts General Hospital (MGH).
ADHD may lead to unhealthy behaviors
ADHD is estimated to affect 8 to 10 percent of school-age children, impacting their ability function at home, in the classroom, and socially. Children and adolescents with ADHD tend to have difficulty paying attention or concentrating, are easily bored or frustrated, and move constantly and impulsively. Because of hormonal changes typical of adolescence, these symptoms can intensify for teens.
Investigators at MGH set out to identify characteristics of children that predicted the development of substance abuse behaviors and whether the characteristics differed by gender.
The study population included children and adolescents from two long-term studies of ADHD—one of boys and one of girls—and provided more than 10 years of follow-up data. A total of 268 young people with ADHD and 209 without ADHD (controls) were evaluated.
Investigators allowed for factors such as gender, mood disorders, school problems, family history of substance abuse, and cognitive difficulties in their analysis. Overall they found that 32 percent of ADHD subjects developed some form of substance abuse, including smoking, compared with 25 percent of controls. Conduct disorder was the only other factor that had an impact, and it tripled the risk of substance abuse in young people with ADHD.
Conduct disorder is often associated with attention deficit disorder. It is difficult to know how many children have conduct disorder, because its characteristics (e.g., defiance, rule breaking, criminal activity) can be hard to define. However, one estimate is that 1 to 4 percent of 9- to 17-year-olds have the disorder, depending on how it is defined.
The study showed that ADHD presented a 1.5 times greater risk of developing substance abuse problems than not having the disorder. According to the study’s leader, Timothy Wilens, MD, of the MGH Pediatric Psychopharmacology Unit, the study “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.”
Wilens noted that “anyone with ADHD needs to be counseled about the risk for substance abuse, particularly if they have any delinquency.” Experts do not know why some young people with ADHD develop substance abuse and smoking behaviors while others do not, and these questions will likely be the subject of additional research.
American Academy of Child & Adolescent Psychiatry
Wilens TE et al. Journal of the American Academy of Child & Adolescent Psychiatry 2011 Jun; 50(6): 543-53