Serum dexamethasone concentrations in endogenous depressives before, during, and after treatment: preliminary observations.

The 1.0-mg Dexamethasone (DEX) Suppression Test (DST) was performed in 10 endogenous depressives prior to treatment, during treatment, and again when the patients were medication- and symptom-free. Five of the 10 patients were DST escapers prior to treatment, and all 10 patients were DST suppressors following treatment. During treatment, 6 patients were DST escapers, 2 of them having been suppressors initially. There were no significant differences in serum DEX concentrations before, during, and after treatment in either the 5 DST escapers or the 5 DST suppressors. These results lend further support to the concept that reduced serum DEX concentrations are not the major factor underlying DST nonsuppression.