Holsboer F, Doerr H G, Sippell W G
Psychiatry Res. 1983 Jan;8(1):49-57. doi: 10.1016/0165-1781(83)90138-5.
The dexamethasone suppression test (DST) based on multisteroid analysis was administered to 22 female patients with primary major depressive disorder (12 endogenous, 10 nonendogenous) and 12 healthy control subjects. Cortisol, its biosynthetic precursor 11-deoxycortisol, and cortisone were measured. Calculating cortisol/11-deoxycortisol ratios allows the assessment of the activity of 11 beta-hydroxylase, which depends on the mean secretion rate of adrenocorticotropic hormone. Preliminary findings indicate that the sensitivity of the DST is remarkably increased when based on a cortisol/11-deoxycortisol ratio instead of plasma cortisol or cortisone concentrations.