Effect of estrogens on the dexamethasone suppression test in nondepressed women.

It is often suggested that estrogens may cause false-positive dexamethasone suppression test (DST) results. In this study of nine healthy, non-depressed women, DSTs were performed at baseline, immediately following administration of 21 days of oral contraceptives containing either 50 or 80 micrograms of mestranol (a synthetic estrogen) in combination with 1 mg of norethindrone (a synthetic progesterone), and 1 month after discontinuing the oral contraceptives. All subjects had post-dexamethasone cortisol levels less than or equal to 5 micrograms/dl during the study with the exception of two subjects in the mestranol 80 microgram group who had positive DSTs immediately following oral contraceptive administration; one of these subjects continued to have a positive DST 1 month later. DST results should be interpreted with caution if high dose estrogens are taken concurrently or have been recently discontinued.