E2 ModeratePreliminaryPEM unclearCross-SectionalPeer-reviewedMachine draft
The Fatigue-Related Symptoms Post-Acute SARS-CoV-2: A Preliminary Comparative Study.
Thomas, Marie · International journal of environmental research and public health · 2022 · DOI
Quick Summary
This study compared fatigue and related symptoms in 26 people experiencing Long COVID with two groups: people without fatigue and people with ME/CFS. The Long COVID group reported severe fatigue, brain fog, sleep problems, and difficulty concentrating—similar to what people with ME/CFS experience. The findings suggest Long COVID and ME/CFS may share some common features.
Why It Matters
This study provides evidence that Long COVID fatigue closely resembles ME/CFS in both symptom severity and psychological burden, suggesting shared pathophysiological mechanisms. Understanding these similarities could help researchers identify risk factors for persistent post-viral fatigue and inform treatment approaches applicable to both conditions.
Observed Findings
- Long COVID participants reported significantly higher fatigue levels and cognitive difficulties than non-fatigued controls.
- Long COVID participants reported more individual symptoms including lack of concentration and sleep quality problems.
- Depression, perceived stress, emotional distress, and cognitive difficulties were similar in magnitude between Long COVID and ME/CFS groups.
- Symptom profiles in Long COVID showed measurable heterogeneity across the 26 participants.
Inferred Conclusions
- Long COVID fatigue shares phenotypic characteristics with ME/CFS, suggesting potential overlapping mechanisms warrant investigation.
- The range and severity of Long COVID symptoms necessitate further research into mechanisms underlying persistent post-viral fatigue.
- Identifying individuals at risk of long-term symptoms and developing targeted interventions should be priorities for clinical care.
Remaining Questions
- What are the biological and immunological mechanisms driving the similarity between Long COVID and ME/CFS fatigue profiles?
- Which pre-infection or acute infection factors predict progression to persistent fatigue in post-COVID populations?
- Are current ME/CFS treatment or management approaches effective for Long COVID patients?
What This Study Does Not Prove
This study does not prove that Long COVID and ME/CFS are the same condition or that they share identical biological causes—it only shows symptom overlap. The cross-sectional design cannot determine whether fatigue severity predicts long-term disability or whether specific symptoms cause others. The small, self-selected sample limits whether findings apply to the broader Long COVID population.
Tags
Symptom:Cognitive DysfunctionUnrefreshing SleepFatigue
Phenotype:Infection-TriggeredLong COVID Overlap
Method Flag:PEM Not DefinedWeak Case DefinitionSmall SampleExploratory Only
Metadata
- DOI
- 10.3390/ijerph191811662
- PMID
- 36141935
- Review status
- Machine draft
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 8 April 2026
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 →
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