A family study of chronic post-traumatic stress disorder following rape trauma.

There is evidence that familial factors serve as determinants of risk for post-traumatic stress disorder (PTSD), especially familial anxiety. This study investigates the relationship between chronic PTSD and family psychiatric morbidity. The sample was drawn from 81 female rape survivors with or without lifetime PTSD, 31 major depressive disorder controls, 20 anxiety disorder controls and 39 healthy controls. First-degree family members were directly interviewed (n = 285) and diagnoses assigned of major depressive, anxiety and alcohol or substance use disorder. Information was also available by family history for 639 relatives. In the directly interviewed sample, no consistently increased morbidity risk was observed for anxiety, PTSD, or alcohol/substance abuse in the rape survivor groups, but there was an increase in depression relative to the anxiety in healthy control groups. When comorbid depression in rape survivor probands was taken into account post hoc, an increased risk for depression was noted in family members of PTSD probands with depression, but not in relatives of PTSD probands without lifetime depression. Among rape survivor probands with non-comorbid PTSD, rates by history of familial anxiety and depression were negligible. In a logistic regression analysis, individual vulnerability to depression served as an independent predictor of chronic PTSD, along with specific trauma-related variables. In the family history group, results were consistent with those obtained from the directly interviewed group. Our findings clearly support the view that PTSD following rape is associated with familial vulnerability to major depression, which may thus serve as a risk factor for developing PTSD. The exact nature of this predisposition calls for further inquiry and there is a need to expand this study to include other PTSD populations. PTSD may on occasion represent a form of depression which is induced and/or modified neurobiologically and phenomenologically by extreme stress. Our findings may be a reflection of the sample composition, the current conceptualization of PTSD, or be related to study limitations.