results, it is difficult to draw any definitive conclusions, but the greater similarity of our results to those of Stein et al. (2002) versus Lyons et al. (1993) suggests that the relative contribution of genetic and shared environmental influences may vary by gender and/or nature of the trauma. Again, although rarely reported in other studies, the high genetic correlation we found between trauma exposure and PTSD has also been documented previously (Stein et al. 2002).
