Conduct Disorder and Initiation of Substance Use: A Prospective Longitudinal Study

CD confers increased risk for substance use initiation across all substance classes at age 15 years, with greater relative risk for illicit substances compared to licit substances. This effect continues until age 18 years, with the weakest effect for alcohol. It further diminishes for other substances by age 21, However, the likelihood of initiating cocaine, amphetamines, inhalants and club drug use among those who have not initiated yet continues to be highly elevated by age 21.