Abstract
Independent variables were identified which would statistically discriminate between a group of Vietnam veterans who were experiencing posttraumatic stress disorder and those who were not. DSM-III (Diagnostic and Statistical Manual of Mental Disorders-III) criteria for diagnosis were used to measure and operationally define posttraumatic stress disorder. Five variables distinguished between groups: veterans with the disorder reported a negative perception of their family''s helpfulness on return home, a higher level of combat, a more immediate discharge after the war, an external locus of control, and a more supportive attitude toward the war before they entered the service.