and substance dependence diagnoses were observed (Supplementary Table 7; Fig. 1). Interaction effects of alcohol dependence were observed, such that individuals with a lifetime alcohol dependence diagnosis and higher polygenic risk for PTSD were more likely to have PTSD (B = 0.100, p < 0.01, adjusted-p < 0.05) compared to individuals with higher polygenic risk for PTSD, but without alcohol dependence (Supplementary Table 9; Fig. 2). This finding remained significant after adjusting p-values for multiple testing using the Benjamini–Hochberg procedure. Further, the addition of the problematic alcohol use PRS changed the main effect of the PGC-PTSD PRS on PTSD diagnosis. While the association was still nominally significant (p < 0.05), it was no longer significant with the Benjamini–Hochberg procedure. However, the inclusion of the problematic alcohol use PRSS in the model did not change the significant interaction effect between the PGC-PTSD PRS and alcohol dependence (Supplementary Table 10).
