Mean 14.00–17.00 h plasma cortisol concentration and its relationship to the 1 mg‐dexamethasone suppression response in depressives and controls

Abstract

ABSTRACT– Three‐hour cortisol‐profiles and cortisol responses to a 1 mg dose of dexamethasone were recorded in 31 depressed patients and nine controls. The data indicate that the likelihood of detecting non‐suppressible cortisol concentrations after dexamethasone is significantly increased in depressed patients with a hypersecretion of cortisol. However, a considerable subsample of normosecretors shows abnormal DST results. Conversely, hypersecretion is often associated with dexamethasone suppression. In this study a 1 mg‐DST did not reflect the adrenocortical activity with ultimate accuracy. Therefore any attempts which correlate psychopathological or biological data with pituitary‐adrenal activity and use a DST‐result as measure are criticizable. Data derived from volunteers illustrate that medical factors such as weight‐loss, steroid‐containing contraceptives and sleep deprivation can make a pituitary‐adrenal activity test ambiguous.