ABSTRACT
Four weekly repetitions of the overnight dexamethasone suppression test (DST) in each of 10 healthy volunteers yielded plasma cortisol levels that were consistently suppressed. These results suggest that unlike some dynamic tests of hypothalamic-pituitary functioning, the DST does not produce false-positive results due to weekly repetition. This finding is of interest because previous research has demonstrated that a subgroup of melancholic initial nonsuppressors continue to resist cortisol suppression despite apparent clinical improvement. The present findings do not support the hypothesis that continued nonsuppression in clinically improved patients is an artifact of serial testing.
Subject(s)
Dexamethasone , Hydrocortisone/blood , Adult , Circadian Rhythm , Female , Humans , Kinetics , Male , Radioimmunoassay , Reference ValuesABSTRACT
Fourteen patients with RDC diagnosis of primary, endogenous, major depressive disorder were studied in an inpatient setting. All were non-suppressors on the Dexamethasone Suppression Test on admission to hospital and were retested at discharge. Over 70% of patients continued to be non-suppressors at discharge, when in clinical remission. Four out of 14 patients converted to normal suppression. All 10 of the non-normalizers did poorly on follow-up: 3 patients committed suicide. All normalizers did well. Non-normalization of the DST at discharge from hospitalization may be more common than previously suspected and predicts poor clinical outcome.
