The specificity of the interaction effects for the AUD symptom phenotype is surprising given the evidence of overlap in genetic effects on alcohol dependence and maxdrinks (Grant et al., 2009, Kendler et al., 2010) and Meyers et al.’s (2013b), finding that childhood adversity moderated the influence of rs1229984 on both alcohol phenotypes. The absence of an effect on maxdrinks may be due in part to the distinction between the two alcohol-related phenotypes (although it is unclear why this distinction has not impacted results in other studies). Whereas AUD symptom count is a direct measure of problems resulting from alcohol use, that is pathological use, maxdrinks captures a snapshot of peak alcohol use that may or may not be representative of long-term patterns of alcohol consumption.
