likelihood of selective pressure for this GABRA2 region distal to intron 3 [47]. Two subsequent studies in the COGA dataset have shown that the original evidence for association with AUD derived only from individuals with comorbid illicit drug dependence [48] and in adolescents, GABRA2 is associated with childhood conduct disorder symptoms, known to be a predictor of later-onset AUD [49]. Furthermore, GABRA2 variation appears to influence the subjective response to alcohol [50] and an fMRI study using a monetary incentive delay task has shown that GABRA2 variation is probably associated with impulsivity through variation of insula activity responses [51].
