Among the limitations of the current report is its use of retrospective recall of trauma in adult populations. However, the bias in retrospective reports of childhood adversity tends toward false negatives rather than false positives (Hardt and Rutter 2004). Because all samples are Australian and were either ascertained based on self‐report of childhood trauma exposure, or for genetic studies of substance dependence (populations with high prevalence of childhood trauma compared to general population samples), these results are not necessarily generalizable to population‐based samples. We are encouraged by our finding (Agrawal et al. 2012) of a significant interaction in CAT Study data involving the CPA factor and an endocannabinoid receptor (CNR1) polymorphism (rs1049353) associated with anhedonia and anhedonic depression that replicated a similar interaction involving a binary measure of CPA and rs1049353 genotype in a general population Missouri twin sample. However, additional research will be necessary to demonstrate generalizability. It is likely that not controlling for case status in regression analyses examining association of the CTF with outcomes impacted estimates of risk. We did so to allow greater comparability across studies
