Consistent with the existing literature, phenotypic analyses revealed elevated rates of lifetime AD diagnoses in women who had experienced traumatic events (Fergusson et al. 1996; Kilpatrick et al. 1997; Wilsnack et al. 1997), with an even more pronounced elevation in women meeting lifetime criteria for PTSD (Kessler et al. 1995; Breslau et al. 1997; Danielson et al. 2009). We also found that, among women who reported traumatic events but had no history of PTSD, the likelihood of meeting AD criteria was higher in those who experienced assaultive versus only nonassaultive traumas (paralleling the elevated rates of PTSD in victims of assaultive events). Genetic analyses produced heritability estimates of 28%, 72% and 71% for trauma exposure, PTSD and AD respectively, and indicated that trauma exposure and PTSD were attributable to the same source of genetic variance. Whereas only additive genetic and individual-specific environmental influences were evident for PTSD and AD, shared environmental factors were also found to play a role in trauma exposure, accounting for 33% of variance. Of greatest relevance to our primary research question, we found that the genetic
