Repeated Cortisol Awakening Response as Predictor of Antidepressant Treatment Outcome with Duloxetine

Abstract

Background: Despite considerably extended knowledge about the mechanism of action of antidepressants, physicians would greatly benefit from reliable biological predictors identifying those patients who will respond poorly to a given treatment. The aim of the present study was to assess whether repeated testing of the cortisol awakening response (CAR) between baseline and after 10 days of duloxetine treatment is able to predict antidepressant treatment outcome after 6 weeks of treatment. Methods: 12 patients with a major depressive episode were treated with duloxetine 90 mg/day for 6 weeks. At baseline and after 10 days of duloxetine treatment, the CAR was assessed, and changes between baseline and day 10 were categorized as improved or unimproved according to the change in cortisol area under the concentration-time curve total concentrations. Depression severity was assessed with the 21-item Hamilton Depression Rating Scale (HDRS-21). Results: Non-remission after 6 weeks of treatment with duloxetine was predicted by an unfavourable saliva cortisol change between baseline and 10 days of duloxetine treatment. Linear regression analysis revealed that patients with a higher decrease in saliva cortisol measures between baseline and 10 days of treatment show a higher decrease in HDRS-21 scores. Conclusion: Repeated CAR during early treatment is a putative predictive marker of antidepressant treatment outcome with duloxetine.