We use data from a large epidemiological study to examine the influence of selected predispositions on PTSD induced by an extreme trauma – sexual assault – relative to their influence when events are of lower magnitude. Six predispositions are examined: pre-existing major depression (MDD), generalized anxiety disorder (GAD), alcohol-use disorder (AUD), and parental history of alcohol problems, drug problems and incarceration. The classification of sexual assault as an extreme trauma is based on the consistent epidemiological findings of high PTSD risk associated with it (e.g. Kessler et al. 1995; Breslau et al. 1998b, 2004b). Three event types of lower magnitude were selected for comparison: accidents, disaster and unexpected death of a close friend/relative. Epidemiological evidence on the conditional risk of PTSD supports the classification of these as lower-magnitude events (Kessler et al. 1995; Breslau et al. 1998, 2004). We compare the influence of each predisposition on the PTSD risk associated with sexual assault relative to accidents, disaster and unexpected death of someone close, in this order.
