Familial psychiatric illness and posttraumatic stress disorder: Findings from a family study of substance abuse and anxiety disorders

Background. Aside from the possibility of a direct relationship between ind ividual and familial posttraumatic stress disorder (PTSD), there is accumul ating evidence that implicates a family history of psychiatric and substanc e use disorders as an important risk factor in the development of PTSD and associated symptoms. Method: The familial risk of DSM-III-R PTSD was examined within a family st udy of clinical- and community-ascertained probands (N = 263) and their 120 6 adult first-degree relatives. Results: Although PTSD among probands was not found to significantly elevat e the risk of PTSD among first-degree relatives, an elevated rate of PTSD w as found among the relatives of drug abusing probands compared with the rel atives of probands with alcoholism, other anxiety disorders, and normal con trols. Additionally, affective disorders were significantly associated with PTSD in relatives (p < .01). When these familial and individual associatio ns were examined according to gender, drug disorders in probands were signi ficantly associated with PTSD only among mate relatives (p < .01), while th e association between PTSD and comorbid affective disorders was seen primar ily among female relatives (p < .01). Conclusion: Although probands in the present family study were not selected specifically for PTSD, the data afforded a unique opportunity to examine t he profile of familial psychopathology as a part of the complex picture of susceptibility for PTSD. Future family study research will be able to deter mine the generalizability of the present findings through more complete mea surement of diverse forms of trauma.