RESUMO
Plasma cortisol and 11-deoxycortisol were measured in 30 depressed patients and 110 normal volunteers before and after a 1.0 mg dexamethasone suppression test (DST). Post-dexamethasone plasma cortisol, 11-deoxycortisol and the cortisol/11-deoxycortisol ratio were significantly higher in the depressives compared to the controls, even when age and sex were taken into account. Pre-dexamethasone plasma cortisol, post-dexamethasone cortisol, 11-deoxycortisol and their ratio were significantly higher in the cortisol nonsuppressors than in the suppressors. The measurement of post-dexamethasone 11-deoxycortisol and the ratio did not differentiate between endogenous and reactive depression. Using the normative data, we explored several methods for determining a criterion value to define abnormal post-dexamethasone plasma 11-deoxycortisol and the cortisol/11-deoxycortisol ratio in depressed patients. All showed poor sensitivity and a low positive predictive value for depression. The measurement of 11-deoxycortisol thus does not enhance the clinical utility of the DST.
Assuntos
Cortodoxona/sangue , Transtorno Depressivo/sangue , Dexametasona , Hidrocortisona/sangue , Adulto , Idoso , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/fisiopatologia , Masculino , Pessoa de Meia-Idade , Sistema Hipófise-Suprarrenal/fisiopatologia , Escalas de Graduação Psiquiátrica , Valores de ReferênciaRESUMO
Dexamethasone pharmacokinetics were measured in 19 depressed patients, 10 dexamethasone suppression test (DST) nonsuppressors and nine suppressors, following a 1 mg oral dose in tablet form at 2300 h. Median dexamethasone concentrations were significantly lower in the nonsuppressors from 3-16 hr post-administration. Nonsuppressors had a significantly lower area under the curve than suppressors, and plasma clearance was significantly faster in the nonsuppressors than in the suppressors. Eleven patients, six nonsuppressors and five suppressors, agreed to a repeat DST after clinical improvement when all six nonsuppressors had normal DST responses. There were no significant differences between the median dexamethasone concentrations, or any of the pharmacokinetic parameters measured, of the "normalising" nonsuppressors and the suppressors. Dexamethasone kinetics were altered in depressed nonsuppressors but became normal with remission of depressive symptoms and normalisation of the DST response.
