Interestingly, although Trucco et al. [12] did not find a direct effect of GABRA2 on adolescent alcohol problems, they did find that GABRA2 predicted adolescent alcohol problems indirectly, through mid-adolescent rule-breaking behaviors. Perhaps researchers have not found a direct association between GABRA2 and adolescent alcohol phenotypes because this relation is indirect, and operates through other risk factors. Thus, it is important to examine earlier mediating mechanisms of the relation between GABRA2 and adolescent alcohol problems. Finally, few studies to our knowledge have examined the association between GABRA2 and hyperactive–inattentive symptoms, which is surprising given that GABRA2 has been previously theorized to confer risk for a broad spectrum of externalizing problems [27].
