Moreover, it is important to note that if different alleles of GABRA2 do predict externalizing phenotypes through different mechanisms, the fact that many of these mechanisms might also be correlated could confound the direction of association. For example, if opposing risk alleles within GABRA2 actually predict different, but correlated, intermediate phenotypes, then the effect of GABRA2 on one of the intermediate phenotypes might be masked or reversed if the other phenotype is not included in the model. To further understand the role of GABRA2 on externalizing problems, it will be important to elucidate these possible intermediate phenotypes and test them simultaneously and/or use these intermediate phenotypes as covariates. Based on this reasoning, it should be emphasized that the current results are not necessarily informative as to which phenotypes are related to major vs. minor alleles within GABRA2 SNPs. There may be other intermediate phenotypes not tested in the current study that act as confounding variables. Thus, although our results provide very preliminary insights into the mediating mechanisms in the relation between GABRA2 and externalizing phenotypes, they also point to the
