A pilot study of the phase angle between cortisol and melatonin in major depression - a potential biomarker? Academic Article uri icon

Overview

abstract

  • INTRODUCTION: Hypothalamic-pituitary-adrenal (HPA) axis and melatonin rhythm alterations have been independently reported in major depression (MDD) as well as in insomnia. In this pilot study, we link cortisol and melatonin rhythms and propose that the phase angle between cortisol acrophase (CA) and dim-light melatonin onset (20 pg/ml) (DLMO-20) may yield a useful state specific biomarker for MDD. METHODS: Six healthy (HC) and six depressed (MDD) psychotropic free subjects were admitted to the General Clinical Research Center. Blood was sampled for cortisol and melatonin from 1600h to 1000h, under dim lights (<20lux) and constant routine. Time for DLMO-20 and peak cortisol concentration was determined for each subject. Phase angle was computed as the difference in time between CA and DLMO-20. RESULTS: Phase angle was significantly increased in MDD's versus HC's (13.40+/-1.61h. versus 11.61+/-1.66h, p=0.026). Using ROC analysis, a phase angle greater than 13.57h distinguished MDD's from HC's (sensitivity=0.83, specificity=1.0). Mean nocturnal melatonin (1600-1000h) was significantly decreased in MDD's versus HC's (22.67+/-9.08 pg/ml versus 47.82+/-14.76 pg/ml, p=0.015). CONCLUSIONS: The phase angle between CA and DLMO-20 appears to distinguish HC's from MDD's and may be a useful biomarker to aid biologic assessment as well as treatment. Lower nocturnal melatonin in MDD's highlights its importance in MDD's pathophysiology. Additional study with larger sample size is needed to confirm the results of this pilot study. The mechanism for this phase angle difference and decreased melatonin, itself, requires further study.

publication date

  • December 11, 2009

Research

keywords

  • Circadian Rhythm
  • Depressive Disorder, Major
  • Hydrocortisone
  • Melatonin

Identity

Scopus Document Identifier

  • 73749086978

Digital Object Identifier (DOI)

  • 10.1016/j.jpsychires.2009.06.012

PubMed ID

  • 20004915

Additional Document Info

volume

  • 44

issue

  • 2