The physio-affective phenome of major depression is strongly associated with biomarkers of astroglial and neuronal projection toxicity which in turn are associated with peripheral inflammation, insulin resistance and lowered calcium. — CFSMEATLAS
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The physio-affective phenome of major depression is strongly associated with biomarkers of astroglial and neuronal projection toxicity which in turn are associated with peripheral inflammation, insulin resistance and lowered calcium.
Al-Hakeim, Hussein Kadhem, Al-Naqeeb, Tabarek Hadi, Almulla, Abbas F et al. · Journal of affective disorders · 2023 · DOI
Quick Summary
This study examined whether brain and nerve damage markers in the blood are connected to depression symptoms and other physical complaints. Researchers measured several proteins in the blood of people with depression and compared them to healthy controls, finding that markers of brain cell and nerve damage—along with inflammation and insulin resistance—together explained about 61% of the severity of depression, anxiety, fatigue, and physical symptoms.
Why It Matters
For ME/CFS patients, this work is relevant because ME/CFS shares significant overlap with depression and anxiety, and both conditions involve fatigue, physical symptoms, and potential neuro-immune dysfunction. Understanding whether peripheral markers of neuronal and glial damage contribute to the constellation of depressive and somatic symptoms may illuminate shared pathophysiological mechanisms and guide future diagnostic or therapeutic approaches in post-viral and chronic fatigue conditions.
Observed Findings
Serum GFAP, NF-L, P-tau217, and PDGFR levels were elevated in MDD patients and positively associated with the severity of depression, anxiety, fatigue, and somatic symptoms.
HOMA2-IR (insulin resistance) and CRP (inflammation) were elevated and positively associated with neuroaxis damage markers and symptom severity.
Serum calcium levels were lower in MDD patients and inversely associated with both neuroaxis damage markers and symptom severity.
The four neuroaxis biomarkers plus HOMA2-IR and low calcium collectively explained 61.1% of variance in the combined physio-affective phenome.
Network enrichment analysis revealed these biomarkers cluster in pathways related to glial cells, neuronal projections, cytoskeleton, axonal transport, and mitochondrial function.
Inferred Conclusions
Peripheral inflammation and insulin resistance may damage astroglial and neuronal projection structures, impairing mitochondrial transport and axonal function.
This neurotoxicity, combined with systemic inflammation, insulin resistance, and hypocalcemia, may partially drive the depressive, anxious, fatigue-related, and somatic symptom profile in MDD.
Astroglial and neuronal damage biomarkers partially mediate the relationship between peripheral inflammation/calcium and depressive-affective-somatic symptoms.
Remaining Questions
Does this biomarker profile occur in ME/CFS patients, and if so, does it correlate with fatigue and post-exertional malaise severity?
What This Study Does Not Prove
This cross-sectional study cannot prove causality—it cannot determine whether elevated neuroaxis biomarkers cause depressive symptoms or whether the depressive state elevates these biomarkers. The study is conducted in MDD patients and does not directly test whether these mechanisms apply to ME/CFS. Association does not imply that targeting these biomarkers will improve symptoms.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →