The authors designed a study to identify those independent variables
which would statistically discriminate between a group of Viet Nam veterans
who were experiencing posttraumatic stress disorder and those who were not.
DSM-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. The
authors discuss the implications and limitations of these findings.