Cortisol levels in plasma after dexamethasone administration and the nosology of depression.

The authors have studied 89 depressed patients diagnosed according to three different systems: DSM-III, Kiloh and Garside, Winokur. They administered 1 mg of Dexamethasone at 11 pm; blood samples were taken at 8 am and 8 pm the next day. They find the most significant differences in cortisol levels according to the DSM classification whereas there are no significant differences according to the Winokur classification. They refer the great variance obtained in the endogenous groups to a high incidence of suppressors in these non-suppressor groups. In 26 non-depressed patients, they found 10 non-suppressors. According to the authors, these results demonstrate the importance of DST and other biological tests in the reformation of nosology in psychiatry.