Exploring the Link between ADHD and Cannabis Use in Swedish Ninth Graders: The Role of Conduct Problems and Sensation-Seeking.

: Attention deficit hyperactivity disorder (ADHD) has in several studies been linked to substance use, including cannabis use. However, crucial gaps remain regarding how to understand this association. Analyzing the association between ADHD and substance use is complicated because of a pronounced overlap between ADHD, conduct problems, and traits such as sensation-seeking. : Using data from a large and nationally representative study among Swedish adolescents, this study explored the role of conduct problems, but also of sensation-seeking, in accounting for the association between ADHD and cannabis use. : There was a notable association between ADHD and cannabis use that was attenuated when conduct problems were controlled for. The association between cannabis use and conduct problems, in turn, was attenuated when sensation-seeking was controlled for. Individuals with both ADHD and conduct problems were more likely to have used cannabis than individuals with ADHD only, but not compared with individuals with conduct problems only. : Whereas conduct problems largely explain the link between ADHD and cannabis use, sensation-seeking seems to account for the association between conduct problems and cannabis use.