Cortisol responses to combined dexamethasone/CRH test in outpatients with a major depressive episode

The DEX/CRH test is now a well established method to test the hypothalamic-pituitary-adrenal (HPA) axis for depressed patients in an inpatient setting. The aim of this study was to evaluate this test in an outpatient population suffering from major depression compared to a healthy control group. The main result is a statistically significant difference concerning the delta value for cortisol plasma value on the DEX/CRH test for depressed patients with two or more previous episodes compared to healthy controls. On the contrary, the difference was not statistically significant for patients with only one or no previous episodes. In future studies, it could be interesting to use this test more specifically by dividing ambulatory patients into subgroups according to their past depressive history. It could also be interesting to measure the ACTH level.