Risk factors and posttraumatic stress disorder: are they especially predictive following exposure to less severe stressors?

BACKGROUND: The diagnosis of posttraumatic stress disorder (PTSD) requires exposure to a traumatic stressor, as defined by Criterion A in the DSM criteria for PTSD. Yet, over the course of successive revisions of the diagnostic manual, the range of qualifying stressors has expanded considerably (e.g., watching terrorist attacks on television). Moreover, stressors that fall short of qualifying for even an expanded Criterion A can produce apparent PTSD. Taken together, these findings imply that people who do satisfy symptomatic criteria for PTSD following exposure to less severe stressors carry a heavy burden of risk factors.
METHOD: To test this hypothesis, we examined whether the association between the risk factor of lower intelligence and more severe PTSD and depression symptoms would be greater among women reporting less severe CSA (n = 15) relative to women who reported moderate (n = 54) or high (n = 31) severity CSA.
RESULTS: The evidence was consistent with this hypothesis for subjects in the low and moderate severity groups, but less so for those in the high severity group.
CONCLUSIONS: Lower intelligence was a more potent risk factor for posttraumatic distress among people exposed to less severe relative to moderately severe stressors.