Familial vulnerability factors to post-traumatic stress disorder in male military veterans.

The question has been frequently raised about whether there are emotional disorders that predispose to post-traumatic stress disorder (PTSD). We do know that those with PTSD do have many comorbid disorders, but due to the difficulty in performing prospective studies it is hard to tell what is cause and what is effect. This study bypassed the problem caused by comorbidity by examining family history of four proband groups: PTSD, mixed anxiety disorders, coexisting anxiety and depressive disorders, and screened normal controls. Two questions were examined. First, whether family history predicted who experienced combat situations and second, whether the proband groups could be distinguished by family history. Logistic regression identified two variables that predicted the experience of combat: major depression (odds ratio 2.17) and the DSM-III dramatic personality disorder cluster (odds ratio 1.36). Although there was considerable overlap, family history variables distinguished PTSD from other proband groups. Overall, the pattern of psychopathology in the families of the PTSD probands most closely resembled that in the families of the coexisting anxiety and depressive disorders probands. We conclude that family history methods may be an addition to possible variables that predict who will be exposed to combat and also that family history variables may be able to distinguish a PTSD population from some other types of emotional disorders.