Does Arginine Vasopressin Reflect HPA-axis Activation in Major Depressive Disorder?

Hossein P Nazarloo,Brandon Hage,Angelos Halaris,C Sue Carter,Jasleen Singh

doi:10.31487/j.cei.2020.02.01

Abstract

Researchers have endeavored to subclassify depressive illness based on pathophysiological mechanism. One model relates to hypothalamic-pituitary-adrenal (HPA) axis overactivation with a shift from corticotropin-releasing hormone (CRH) driven regulation to arginine vasopressin (AVP) driven regulation. Given the mixed literature, we compared plasma AVP levels in healthy controls to patients with major depressive disorder (MDD). Plasma samples from 33 patients and 12 controls were collected at baseline, 8 weeks, and 12 weeks of treatment and measured by immunochemical assay. Patients who were treatment responders trended toward lower AVP levels than non-responders. Patients were stratified into low and high AVP groups based on median split. Within the low AVP group, patients whose current episode lasted longer than a year had significantly higher baseline AVP levels than patients whose current episode was less than 6 months. Female patients in the low AVP group had significantly higher baseline AVP levels than male patients. Given the association between stress, HPA axis activation, immune dysregulation, and depression, we also measured concentrations of inflammatory biomarkers. We found a significant negative correlation between IL-10 and baseline AVP levels, within the low AVP subgroup. Given inconsistent data, HPA axis overactivation may be present within a subset of depressed patients.

Highlights

Major depressive disorder (MDD) is a major cause of disability afflicting significant portions of the population worldwide
No significant correlations were found between arginine vasopressin (AVP) levels and severity for depression or anxiety
A meta-analysis of plasma AVP levels found no significant difference between healthy controls and patients with depression

Summary

Introduction

Major depressive disorder (MDD) is a major cause of disability afflicting significant portions of the population worldwide. According to the World Health Organization, MDD impacts over 300 million people throughout the world, with nearly 800,000 people successfully committing suicide annually (“Depression,” 2018). The causes of depression are multifactorial, with stress playing a key role in conjunction with genetic and epigenetic contributions to its etiopathology. Current treatment regimens include a variety of antidepressant medications, with or without psychotherapy, and various augmentation strategies to improve outcome. The gold-standard of remission is only achieved in about one third of patients receiving drug treatments, such as selective serotonin (SSRI), or selective serotoninnorepinephrine (SNRI) reuptake inhibitors. A variety of adjunctive medications are often required with variable success rates. Researchers continue to investigate mechanisms that contribute to the pathophysiology of depression that could identify new targets for drug development

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