Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways

Maes, M., Berk, M., Goehler, L., Song, C., Anderson, G., Gałecki, P. and Leonard, B. (2012) Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways. BMC Medicine, 10(66), (doi: 10.1186/1741-7015-10-66)

Abstract

It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Anderson, Mr George
• Authors: Maes, M., Berk, M., Goehler, L., Song, C., Anderson, G., Gałecki, P., and Leonard, B.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > General Practice and Primary Care
• Journal Name: BMC Medicine
• Publisher: BioMed Central
• ISSN: 1741-7015
• Published Online: 29 June 2012
• Copyright Holders: Copyright © 2012 The Authors
• First Published: First published in BMC Medicine 10:66
• Publisher Policy: Reproduced under a Creative Commons License