HPA AXIS DYSFUNCTION IN DEPRESSION - CORRELATION WITH MONOAMINE SYSTEM ABNORMALITIES

Abnormality of the hypothalamic-pituitary-adrenal (HPA) axis has been one of the most consistently demonstrated biological markers of depres sive disorder. It has also been proposed that abnormality of monoamine function plays a role in the pathogenesis of the disorder. In order t o examine the interrelationships of the HPA axis with the dopaminergic , noradrenergic, and serotoninergic systems, we studied, in 52 medicat ion-free inpatients with DSM-IV nonpsychotic major depressive disorder , the relationship between dexamethasone suppression test (DST) status and a series of multihormonal responses to apomorphine (APO), clonidi ne (CLO), and D-fenfluramine (FEN) tests. DST nonsuppressors did not p resent any difference compared with suppressors in growth hormone (GH) and cortisol stimulation by APO suggesting that a chronic elevation o f cortisol did not lead to an alteration of dopaminergic activity in t his population of nonpsychotic depressed inpatients. Cortisol and prol actin responses to FEN were comparable in nonsuppressors and in suppre ssors. In contrast, GH response to CLO was lower in DST nonsuppressors than in suppressors (p<.03), suggesting that the HPA abnormality indi cated by a positive DST may be related to alpha(2)-adrenoreceptor dysf unction. (C) 1997 Elsevier Science Ltd.