Longitudinal effects of the SSRI paroxetine on salivary cortisol in Major Depressive Disorder

Hypothalamic-pituitary-adrenal (HPA)-axis dysregulation is a prominent finding in more severe Major Depressive Disorder (MDD), and is characterized by increased baseline cortisol levels at awakening (BCL), blunted cortisol awakening response (CAR) and increased area under the cortisol curve (AUC). Selective serotonin reuptake inhibitors (SSRIs) appear to normalize HPA-axis dysfunction, but this is hardly investigated longitudinally. We studied salivary BCL, CAR and AUC at awakening and 30 min thereafter. We compared measurements in initially drug-free MDD-patients with healthy controls (HCs) at study-entry. In patients, we repeated measures after 6 and 12 weeks' treatment with the SSRI paroxetine. Non-responding patients received a randomized dose-escalation after six weeks' treatment. We found no significant study-entry differences in BLC, CAR or AUC between MDD-patients (n = 70) and controls (n = 51). In MDD-patients, we found general decreases of BCL and AUC during paroxetine treatment (