block and externalizing disorders [17, 19, 21]. Interestingly, one study showed that alcoholics with high trait anxiety had a higher abundance of the major haplotype, while alcoholics with low trait anxiety had a higher abundance of the minor haplotype [69], suggesting that minor vs. major haplotypes of GABRA2 might confer risk for externalizing problems through different mechanisms [4]. More research is needed to understand this phenomenon, especially in adolescence.
