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Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways.
Michael Maes1, Michael Berk, Lisa Goehler
1Maes Clinics @ TRIA, Piyavate Hospital, 998 Rimklongsamsen Road, Bangkok 10310, Thailand. dr.michaelmaes@hotmail.com
BMC Medicine
|July 4, 2012
Summary
Sickness behavior, a response to inflammation, shares symptoms with depression. While sickness behavior aids recovery, chronic inflammation in depression can cause neurodegeneration and lasting cognitive issues.
Area of Science:
- Neuroscience
- Immunology
- Psychiatry
Background:
- Sickness behavior is an adaptive response to infection, mediated by pro-inflammatory cytokines, characterized by behavioral inhibition, anorexia, fatigue, and cognitive changes.
- Clinical depression exhibits phenomenological similarities to sickness behavior, including anhedonia, fatigue, anxiety, and neurocognitive deficits.
Purpose of the Study:
- To investigate the relationship between sickness behavior and clinical depression.
- To elucidate the shared immuno-inflammatory pathways underlying both conditions.
Main Methods:
- Comparative analysis of phenomenological and pathophysiological features of sickness behavior and depression.
- Review of immuno-inflammatory mechanisms, oxidative stress, and autoimmune responses in depression.
Main Results:
- Shared immuno-inflammatory pathways link sickness behavior and depression, explaining overlapping symptoms.
- Depression involves a transition to sensitized immuno-inflammatory pathways, oxidative stress, and autoimmune responses, leading to neuroprogressive damage.
Conclusions:
- Sickness behavior represents an acute, adaptive inflammatory response, while chronic inflammation in depression can lead to neurodegeneration and lasting sequelae.
- Inflammation has a dual role: protective in sickness behavior and detrimental in chronic depression, creating positive feedback loops with neurodegeneration.
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