ACUTE ADMINISTRATION OF BUSPIRONE INCREASES THE ESCAPE OF HYPOTHALAMIC-PITUITARY-ADRENAL-AXIS HORMONES FROM SUPPRESSION BY DEXAMETHASONE INDEPRESSION

Recently, our laboratory found a significant enhancing effect of L-5-h ydroxy-tryptophan (L-5-HTP) on post-dexamethasone (DST) plasma adrenoc orticotropic hormone (ACTH) and cortisol levels in major-but not in mi nor-depression. To further elucidate the effects of central serotonin (5-HT) activity on the negative feedback of glucocorticoids on hypotha lamic-pituitary-adrenal (I-IPA)-axis function in depression, this stud y investigates the effects of buspirone, a 5-HT1A receptor agonist, on post-DST ACTH and cortisol levels in 75 depressed subjects. Plasma po st-DST ACTH and cortisol concentrations were significantly increased b y the acute administration of buspirone (30 mg PO) compared to placebo . There were no differences in buspirone-induced post-DST ACTH or cort isol responses between minor and major depression. There were signific ant correlations between post-DST ACTH and cortisol, and between post- DST-buspirone ACTH and cortisol. The buspirone-induced post-DST cortis ol responses were significantly higher in depressed women than men. It is concluded that buspirone may augment ACTH and, consequently, corti sol escape from suppression by dexamethasone in major as well as in mi nor depression.