Although developmental pathways emanating from early childhood that lead to SUDs are rarely articulated in the literature, one notable exception is the antisocial or externalizing pathway. The externalizing pathway is posited to first emerge as difficult temperament in infancy which is followed in childhood by externalizing symptoms (e.g., aggression and conduct problems), an early onset of substance use, escalations in antisocial behavior and the eventual onset of SUDs (Tarter et al., 1999; Zucker et al., 2006). The core behavioral problems of this pathway thus typically reflect behavioral disinhibition, “an inability to inhibit socially undesirable or restricted actions” (p. 326, Iacono, Malone, & McGue, 2008). Although multiple factors may propel youth down this trajectory, current models emphasize interactions between an underlying liability for behavioral disinhibition (due to genetic and neurobiological factors) and a high-risk environment (due to the impact of parent antisociality on impaired parenting, disruptive or impoverished contexts, and deviant peer networks) as core to risk formation (e.g., Hussong, Curran, & Chassin, 1998; Zucker et al., 2006).
