The DST and posttraumatic stress disorder.

The dexamethasone suppression test (DST) was administered to 28 male combat veterans with posttraumatic stress disorder. Six subjects (21%) were nonsuppressors. The nonsuppression rates for the subgroups with and without major depressive disorder according to the Research Diagnostic Criteria were 50% and 6%, respectively. The authors conclude that cortisol nonsuppression is rare in posttraumatic stress disorder unless there is concomitant major depression.