Impaired reduction of enhanced levels of dehydroepiandrosterone by oral dexamethasone in anorexia nervosa.

Allopregnanolone and dehydroepiendrosterone (DHEA) have been supposed to be involved in some psychiatric disorders including anorexia nervosa (AN). The secretion of DHEA and allopregnanolone occurs in both the brain and the adrenal gland, where it is under the control of the corticotrophin-releasing factor (CRF)/adrenocorticotrophin hormone (ACTH) system, and, according to the increased CRF/ACTH drive found in AN, we previously reported enhanced morning levels of both DHEA and allopregnanolone in underweight anorexic patients. To further characterize the physiology of these neurosteroids in AN, we measured plasma levels of cortisol, DHEA and allopregnanolone after the oral administration of 1 mg dexamethasone at 800h in six underweight AN women and ten age-matched healthy females. We found that, before dexamethasone administration, both cortisol and DHEA plasma concentrations were significantly increased in anorexic patients as compared to controls, whereas plasma allopregnanolone levels although increased in the former did not reach a statistical significance. Moreover, while cortisol levels after dexamethasone administration were suppressed in AN to values similar to normal controls, DHEA concentrations, although significantly decreased, remained higher than in normal controls. These data support the view that in AN, the increased production of DHEA may be linked to mechanisms other than the enhanced CRF/ACTH drive.