This study contributes to the increasing literature on the effect of GABRA2 on behaviors characterized by poor effortful control, namely externalizing behavior in adolescence and impulsive personality in adults, both risk factors for alcohol use disorder (AUD). However, the direction of the association is not clear as evidenced by prior work. Several authors have reported the minor allele of the SNPs in high LD as the risk allele in AUD (Covault et al. 2004; Edenberg et al. 2004; Lappalainen et al. 2005; Pierucci-Lagha et al. 2005; Enoch et al. 2006; Fehr et al. 2006; Bauer et al. 2007) and impulsiveness (Villafuerte et al. 2012) while other authors have reported the major allele as the risk allele for AUD (Agrawal et al. 2006; Lind et al. 2008; Soyka et al. 2008), conduct disorder (Dick et al. 2006b), and externalizing disorder (Dick et al. 2009). The present evidence strongly suggests that the minor GABRA2 allele plays a role in behavioral disinhibition processes. Nonetheless, independent replications are still needed to determine whether the diathesis-stress model will be replicated.
