Forty-three depressed patients in hospital were studied with weekly dexamethasone suppression tests (DSTs) and were followed as out-patients for at least three months after discharge. The detection rate of patients with LHPA axis dysfunction increased from 41% with a single DST to 59% with serial DSTs. There was a poor correlation between weekly post-dexamethasone cortisol levels and Hamilton depression rating scores. In patients with evidence of LHPA axis dysfunction, a DST at discharge discriminated effectively between a good and a poor outcome group; persistent non-suppression was strongly linked with a relapse of depression in the first three months after discharge. In general, our results support previous claims that the DST is a state marker for depressive illness.
