Another possible explanation for the absence of direct relations between ECFs and drug use in adolescents is that youth with poor working memory are more susceptible to the interfering effects of drugs on their behavior (Finn, Justus, Mazas, & Steinmetz, 1999). As a result, they are more susceptible to developing dysfunctional trajectories of drug use. Thus, deficits in working memory and other ECFs might not correlate with drug use and SUD until later in life after the deleterious effects of working memory limitations have had their effect. This explanation is consistent with the findings of Tarter et al. (2003) that early ECF did not predict drug use at age 16 but did predict SUD at age 19.
