Relationships among the TRH, REM latency, and dexamethasone suppression tests: preliminary findings.

The DST and TRH stimulation test (TRHST) were administered to 68 depressed in- and outpatients; 28 subjects also received 2 nights of sleep EEG. Results indicated that (1) the TRHST differentiated RDC endogenous from nonendogenous unipolar subtypes at the 5 but not the 7 IuU/ml threshold, (2) neither order nor timing of DST and TRHST testing affected TRHST response, (3) the TRHST detected subjects not identified by the DST, and (4) REM latency detected some patients (23%) not identified by either the TRHST or DST.