(e.g.,(16)), at least one study has implicated common predisposing influences, such as genetic liability, as the major contributor to the association between casual cannabis use and variability in amygdala volume (17). As this sample of college students included <10 individuals who met criteria for cannabis dependence, we were principally interested in examining whether the top loci that emerged from the GWAS were associated with volumetric differences, whether regional brain volume varied across cannabis users and nonusers and further, whether the effects of top loci on cannabis involvement could be partly attributed to variability in brain volume.
