Hair cortisol in patients with a depressive episode treated with electroconvulsive therapy

Background: There is substantial evidence showing changes in hypothalamic pituitary adrenal (HPA)-axis ac-tivity in patients with major depressive disorder (MDD). Also, there seem to be differences in HPA-axis func-tioning between MDD subgroups. It is however unclear whether hair cortisol concentrations (HCC), which are a stable marker of long-term cortisol levels, are suitable as a biomarker for identifying subgroups in MDD. Methods: We were able to attain valid HCC from a scalp hair sample of sixty-two patients with a major de-pressive episode right before electroconvulsive therapy (ECT). HCC were our main biological outcome measure. We created subgroups using depression severity as defined by the Hamilton Depression Rating Scale, the pre-sence/absence of psychotic symptoms, the presence of melancholia as defined by the CORE and catatonia as defined by the Bush-Francis Catatonia Rating Scale. Results: Our analyses of the total group showed a median HCC of 4.4 pg/mg. We found patients with catatonia (N = 10) to have substantially higher median HCC (8.3 pg/mg) than patients without catatonia (3.8 pg/mg). Although presence of melancholia and depression severity were not significantly associated with HCC, more severe psychomotor agitation was associated with higher HCC. Pre-treatment HCC was not associated with ECT outcome. Strengths and limitations: A complicating factor in interpretation of our results was the large variability in HCC. This could be related to potential confounders such as cardiometabolic and other comorbidities, that were however addressed to the extent possible. Conclusions: HCC is a potential biomarker for MDD patients with severe agitation and/or catatonia. ClinicalTrials.gov: Identifier: NCT02562846.