A diagnostic and family study of posttraumatic stress disorder.

A family history study of 36 patients with chronic posttraumatic stress disorder revealed a positive history of familial psychopathology in 66% of the patients. Alcoholism, depression, and anxiety disorders were the disorders most commonly found. The patients also had a higher prevalence of alcoholic siblings than did a retrospectively derived control group of depressed and anxious male patients. With respect to the proportion of familial anxiety to familial depression, the probands with posttraumatic stress disorder more closely resembled probands with generalized anxiety than probands with depression. Every patient had experienced at least one significant psychiatric illness during his lifetime, most commonly alcohol abuse or depression.