We successfully replicated the significant effects of the interaction between genotype and childhood physical abuse on both anhedonia and on anhedonic MDD in the CATS sample. The continuously distributed abuse factor [mean=0, SD=1] had a strong main effect on anhedonia resulting in 1.59 increased odds of anhedonia for every standard deviation increase in exposure. Next, we compared rates of anhedonia as a function of genotype and exposure to abuse. While childhood abuse was derived as a continuously distributed factor score, for ease of visualization, in Table 2 and Figure 1, the continuous physical abuse measure is shown as the top and bottom quartile and the mid-50%. As shown in Table 2 and Figure 1, rates of anhedonia, irrespective of genotype were highest in those in the top-quartile for exposure to abuse (70.8%). However, in carriers of the A allele (i.e. AA/AG individuals) rates of anhedonia (66.1%) were attenuated in those in the top-quartile for abuse exposure. Unlike MOAFTS, there was no evidence for an additive increase in buffering with increasing copies of the A allele. We also examined whether the
