Plasma 11-deoxycortisol and cortisol following dexamethasone in psychiatric patients.

As it has been suggested that calculating the ratio of cortisol to its biosynthetic precursor, 11-deoxycortisol, may enhance the sensitivity of the dexamethasone suppression test (DST) for depression, cortisol and 11-deoxycortisol were measured in 90 subjects undergoing this test. Among these subjects, post-dexamethasone cortisol and 11-deoxycortisol levels were significantly correlated (r = 0.65, P less than 0.001) and evaluating the ratio of cortisol to 11-deoxycortisol decreased rather than enhanced sensitivity of the DST.