Posttraumatic stress disorder (PTSD) is a severe and persistent pathologic response to trauma that occurs in some, but not all, exposed individuals. Twin studies (True et al., 1993; Sartor et al., 2011; Sartor et al., 2012) have consistently found PTSD to be moderately heritable (e.g., h2=0.46) (Sartor et al., 2012). Genetic factors thus likely play an important role in determining susceptibility among those who have experienced trauma.
