E0 ConsensusModerate confidencePEM ?Systematic-ReviewPeer-reviewedMachine draft
Mapping the brain's fatigue network: a transdiagnostic systematic review and meta-analysis on functional correlates of mental fatigue.
Schumann, Andy, Di Giuliano, Monica, Schulz, Steffen et al. · Brain communications · 2025 · DOI
Quick Summary
Scientists analyzed brain imaging studies from 46 different research projects involving over 2,600 people to understand how fatigue affects the brain. They found that mental fatigue—the kind experienced in ME/CFS, long COVID, and other conditions—involves a network of interconnected brain regions, particularly in areas responsible for thinking, emotions, and body awareness. These brain regions don't communicate properly when people experience severe fatigue, which may explain why fatigue is so hard to overcome.
Why It Matters
This study provides the first comprehensive transdiagnostic map of brain regions involved in mental fatigue, directly supporting ME/CFS research by showing that fatigue involves specific, measurable brain network dysfunction rather than being psychological. Understanding these brain networks is crucial for developing targeted treatments and validating ME/CFS as a neurobiological condition. The findings may help explain why standard treatments for other conditions often fail in ME/CFS patients and guide development of more effective interventions.
Observed Findings
- Brain regions showing abnormal activation in mental fatigue include frontal, limbic (emotional), basal ganglia (motivation/movement), and parietal (sensory/spatial awareness) structures
- Three distinct but interconnected brain clusters were identified: frontal-striatal-limbic, frontal-cingulate, and parietal regions
- Key dysfunctional brain nodes include the lateral prefrontal cortex, anterior cingulate cortex, insula, thalamus, precuneus, and caudate nucleus
- Abnormalities were observed across multiple conditions (ME/CFS, long COVID, depression, multiple sclerosis, and others), suggesting a common neural mechanism
- Thalamic-striatal-cortical dysfunction appears central to mental fatigue pathophysiology
Inferred Conclusions
- Mental fatigue operates through a transdiagnostic brain network rather than condition-specific mechanisms, explaining its presence across diverse diseases
- Thalamic-striatal-cortical circuit dysfunction impairs the brain's compensatory mechanisms, preventing normal adaptation to mental demands
- Abnormal limbic and parietal activation contributes to the cognitive, emotional, and attentional symptoms that accompany fatigue
- Brain network dysfunction provides objective biological basis for mental fatigue, supporting its recognition as a neurobiological rather than purely psychological symptom
What This Study Does Not Prove
This meta-analysis identifies brain regions associated with fatigue but does not prove causation—abnormal activation could be a consequence of fatigue rather than its cause. The study does not test specific treatments or predict which patients will respond to particular therapies. Individual variation in brain activation patterns means these findings describe group-level trends and may not apply equally to all ME/CFS patients.
Tags
Symptom:Cognitive DysfunctionFatigue
Biomarker:Neuroimaging
Method Flag:Weak Case DefinitionMixed Cohort
Metadata
- DOI
- 10.1093/braincomms/fcaf315
- PMID
- 40936649
- Review status
- Machine draft
- Evidence level
- Established evidence from major reviews, guidelines, or evidence maps
- Last updated
- 8 April 2026