Although not classified as disorders of childhood per se, substance use disorders are also common in youth (Young et al., 2002). Childhood conduct disorder is a strong predictor of substance use, abuse, and dependence, which typically develop subsequently. A review of 11 epidemiologic studies examining the comorbidity between adolescent substance use disorders and other psychiatric disorders reported a median prevalence rate of 46% for conduct disorder and/or ODD in youth reporting substance use or a substance use disorder (Armstrong & Costello, 2002). There is also an extensive literature linking personality characteristics such as novelty seeking, impulsivity, and (lack of) constraint with substance use disorders (Cloninger, Sigvardsson, & Bohman, 1988; Howard, Kivlahan, & Walker, 1997; McGue, Iacono, Legrand, Malone, & Elkins, 2001; Sher & Trull, 1994) and antisocial behavior (Caspi, Moffitt, Newman, & Silva, 1996; Finn, Mazas, Justus, & Steinmetz, 2002; Tremblay, Pihl, Vitaro, & Dobkin, 1994). Though these studies clearly implicate a common element of pathology of these childhood disorders and associated personality characteristics, their utility is limited by the absence of explicit hypotheses about the nature of this comorbidity.
