The current investigation extends our understanding of the co-morbidity of PTSD and AD in women by characterizing common genetic and environmental contributions to the two disorders using a large, all-female community-based sample. Ours is the first known study to quantify the degree of overlap in the heritable and environmental influences on PTSD and AD in women and one of only a few to estimate heritability of PTSD in a sample that includes females. The existing literature is based primarily on an all-male twin sample in which combat was the traumatic event that led to PTSD. Our examination of PTSD and AD in an all-female population-based sample allows us both to uncover potential differences by gender in the relative role of genetics versus environment and to study the inter-relatedness of these heritable and environmental influences in the context of a broader range of trauma exposures.
