Morning salivary dehydroepiandrosterone (DHEA) qualifies as the only neuroendocrine biomarker separating depressed patients with and without prior history of depression: An HPA axis challenge study

Abstract

BackgroundHypothalamic-pituitary-adrenal (HPA) axis abnormalities in major depression (MDD) have been consistently reported in psychiatry and extend to several neurosteroids. However, recurrence and chronicity may heavily influence HPA axis dynamics in MDD along its course and also explain conflicting results in literature. Thus, the mechanistic understanding of HPA axis (re)activity changes over time could be of major importance for unravelling the dynamic pathophysiology of MDD. MethodsThis study simultaneously assessed several baseline and dynamic HPA-axis-related endocrine biomarkers in both saliva (dehydroepiandrosterone, DHEA; sulfated DHEA, DHEA-s; cortisol, CORT) and plasma (CORT; adrenocorticotropic hormone, ACTH; copeptin, CoP) over three consecutive days using overnight HPA axis stimulation (metyrapone) and suppression (dexamethasone) challenges in order to investigate differences between antidepressant-free MDD patients (n = 14) with and without history of prior depressive episodes (i.e., first vs. recurrent episode). ResultsOur results suggest group differences only with respect to saliva DHEA levels, with recurrent-episode MDD patients showing overall lower saliva DHEA levels across the three days, and statistically significant differences mainly at day 1 (baseline) across all three timepoints (awakening, +30 min, +60 min), even after adjustment for confounders. ConclusionsOur study supports that salivary DHEA levels could represent a significant biomarker of MDD progression and individual stress resilience. DHEA deserves additional attention in the research of pathophysiology, staging and individualized treatment of MDD. Prospective longitudinal studies are needed to evaluate HPA axis reactivity along MDD course and progression to better understand temporal effects on stress-system-related alterations, related phenotypes and appropriate treatment.