Behavioral Impulsivity in Adolescents With Conduct Disorder Who Use Marijuana

Objective: To test behavioral impulsivity among adolescents with conduct disorder (CD) and a history of marijuana use. Methods: In this case-controlled study of behavioral impulsivity, 13 through 17-year-olds withCDand positive urine-drug screens for marijuana (CD/THC+, n= 11) were compared to: (1) adolescents with CD who had negative urine-drug screens (CD/THC-, n= 11) and (2) healthy adolescents without CD symptoms who had negative urine-drug screens (control, n= 11). Participants (30 boys and 3 girls) completed the immediate memory task to measure response initiation aspects of impulsivity and questionnaires to quantify CD symptoms. Results: Ratings of self-and parent-reported CD symptoms and self-reported lifetime history of drug use were similar between the CD/THC- and CD/THC+ groups. There was a significant stepwise increase in laboratory impulsive responding (on the immediate memory task) across the 3 groups (control < CD/THC- < CD/THC+; P<0.001), with the highest proportion of impulsive responses emitted by the CD/THC+ group. Conclusions: These data suggest that the residual effects of marijuana use may further enhance the already high levels of impulsivity in adolescents with CD, and that performance on response initiation measures of impulsivity may be relevant to understanding behavioral changes accompanying marijuana use.