Regarding polygenic results, a distinction must be drawn between the EA and AA components of this study. For reasons discussed below, the present report was far more informative for PTSD genetics in EA individuals than AA individuals, despite comparable sample sizes (both ∼10 000 with 25% cases). Among EA individuals, these molecular genetic results parallel twin study results6, 7, 8, 9 that showed moderate heritability for PTSD overall and higher heritability in females than males.
