Studying the role of effortful control in the progression from adolescent substance use to early-adult problematic substance use requires taking into account other contextual factors that are also associated with this progression. Research has begun to elucidate the combined role of adolescent self-regulation and these contextual risk factors in predicting adolescent substance use (Dishion and Patterson 2006; Stice and Gonzales 1998; Wills et al. 2001a, b; Wills and Dishion 2004). These researchers argue that self-regulation may serve to moderate contextual risk and thus act as a protective factor. The purpose of our study was to examine the unique and interactive roles of effortful control in the progression from adolescent substance use to abuse and dependence by early adulthood, while taking into account the critical risk factor of friends’ support for drug use in adolescence.
