We propose that the GABRA2 G-G haplotype influences the homeostatic imbalance toward excitation, as evidenced by the electrophysiological anomalies associated with this haplotype 6. This imbalance may intensify the activation of the interoceptive representations within the Insula (higher activation for GG during cue-induced urges), thus contributing to impulsive behaviors 48, 56, 57 related to distress. However, the applicability of these results across the entire sample must be treated with caution given that differences have been observed in the role of GABRA2 in alcoholism risk across development. Specifically, a strong association with alcohol dependence may not emerge until the mid-20’s, whereas association with conduct disorder symptoms is present at earlier ages 48. We interpret the present results to indicate an influence of GABRA2 on the underlying neural system that influences both early risk factors as well as later alcohol dependence. However, prospective, longitudinal studies will be required to support this. Larger samples along with replication of our findings are necessary to elucidate the specific mechanism by which GABRA2 exerts its effect on Impulsiveness-related traits and its role in alcohol addiction.
