Research conducted on the involvement of GABRA2 in alcohol use, impulse control behavior, and environment is indicative of its role in behavior characterized by hyperexcitability, impulsivity, or externalizing spectrum disorder (Dick et al. 2006b, 2009; Villafuerte et al. 2012). Those high in the externalizing trait tend to be more impulsive and sensation seekers (Rubin et al. 2006). Furthermore, genetic variations in this gene have predicted differences in response to the environment. To illustrate the complexity of these relations, Dick et al. (2006a) reported both gene–environment correlation (rGE) and Gene × Environment interaction (G x E) effects of GABRA2 with marital status and with alcohol dependence. A GABRA2 × Parental monitoring interaction has also been shown with externalizing behavior in adolescence; high levels of parental monitoring diminished the association of GABRA2 variants on trajectories of externalizing behavior (Dick et al. 2009).
