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 importance of examining other possible mediators as alternatives. Our results inform directions for future research and provide additional evidence that GABRA2 risk alleles might differently predict externalizing problems across studies because multiple mechanisms of risk exist [4, 69].
