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ME/CFS Atlas — A public knowledge atlas for ME/CFS

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ME/CFS Atlas is an evidence reference platform, not a medical provider. Content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.

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ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

Evidence browser

Search and filter 6,145 studies by evidence level, diagnostic criteria, PEM status, and research domain. Each entry links to the original source.

Studies sorted by evidence level, then year. Browse by topic instead →

Evidence level (E0–E3) reflects study type and replication, not methodological quality. A weak systematic review still sits at E0. How evidence levels work →

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510 studies

E0 — Consensus637E1 — Replicated320E2 — Moderate2,768E3 — Preliminary2,420

ME/CFS4,014Long COVID212Post-infectious189Overlapping1,045

Required for diagnosis412Not specified / unclear2,201Not required3,532

Post-Exertional Malaise1,055Cognitive Dysfunction1,723Pain1,612Unrefreshing Sleep793Orthostatic Intolerance474

Cytokines816Gene Expression567Metabolomics469Neuroimaging466Autoantibodies457

Infection-Triggered1,170Long COVID Overlap580Pediatric492Severe228

Strong Phenotyping435Sex-Stratified326Severe ME Included116

Systematic Review263Meta-Analysis60RCT300

Peer-reviewed6,088Preprint3Unclear54

321–340 of 510 studies

E3 PreliminaryCohortPEM unclearCross-Sectional

"It´s incredible how much I´ve had to fight." Negotiating medical uncertainty in clinical encounters.

Lian, Olaug S, Robson, Catherine·International journal of qualitative studies on health and well-being·2017

This study asked 256 people with long-term unexplained fatigue in Norway to describe their experiences with doctors. Most patients felt their doctors didn't believe them, gave unhelpful psychological explanations, didn't do proper physical exams, and didn't listen to what they knew about their own condition. Patients described these encounters using words like 'fighting' and 'war,' showing how stressful and adversarial these medical visits felt.

E3 PreliminaryDiagnosticPEM unclearCross-Sectional

Assessing current functioning as a measure of significant reduction in activity level.

Thorpe, Taylor, McManimen, Stephanie, Gleason, Kristen et al.·Fatigue : biomedicine, health & behavior·2016

ME/CFS diagnosis requires patients to show a significant drop in their activity levels, but doctors haven't agreed on how to measure this drop consistently. This study tested whether a common health survey (the SF-36) could accurately measure when someone's activities have substantially decreased. The researchers found that certain parts of this survey do a good job of identifying major reductions in functioning and can distinguish ME/CFS patients from healthy people.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Chronic fatigue syndrome and sleep disorders: clinical associations and diagnostic difficulties.

Ferré, A·Neurologia·2016

This review looked at the connection between ME/CFS and sleep problems. Many people with ME/CFS experience non-restorative sleep (where sleep doesn't feel refreshing) and fatigue, but these same symptoms can happen with other sleep disorders. The key finding is that doctors need to carefully check whether patients have a separate sleep disorder before or alongside an ME/CFS diagnosis, because treating the sleep problem might help improve overall quality of life.

SleepDiagnostics

E3 PreliminaryReviewPEM not requiredReview-Narrative

[Chronic fatifue syndrome.].

Holecek, V, Rokyta, R·Ceskoslovenska fysiologie·2016

This review article provides an overview of ME/CFS, explaining what it is, how common it is, and how doctors diagnose and treat it. The condition lasts about 6 months or longer in adults and at least 3 months in children, causing persistent fatigue and other symptoms. The article covers multiple possible causes including biological, genetic, infectious, and psychological factors, as well as the economic impact of the disease.

E3 PreliminaryReviewPEM unclearReview-Narrative

Severity Scales for Use in Primary Health Care to Assess Chronic Fatigue Syndrome/Myalgic Encephalomyelitis.

Hardcastle, Sharni Lee, Brenu, Ekua Weba, Johnston, Samantha et al.·Health care for women international·2016

ME/CFS affects people very differently—some have mild symptoms while others are severely disabled. This study reviewed different tools doctors can use to measure how severe a patient's ME/CFS is based on their symptoms and ability to function physically and mentally. Using these measurement tools helps doctors and researchers identify different groups of ME/CFS patients, which could lead to better diagnosis and treatment.

E3 PreliminaryCommentaryPEM unclearEditorial

Investigating unexplained fatigue in general practice with a particular focus on CFS/ME.

Bansal, Amolak S·BMC family practice·2016

This paper looks at how doctors in general practice can identify ME/CFS in patients who come in complaining of unexplained tiredness. The authors explain that ME/CFS is a real condition with specific diagnostic criteria, and that normal blood tests (ruling out infections, thyroid problems, and other common causes) combined with careful clinical assessment can confidently diagnose it. They argue that early diagnosis in primary care can reduce patient worry and prevent unnecessary, costly tests.

E3 PreliminaryCohortPEM unclearCross-Sectional

Implementing resources to support the diagnosis and management of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in primary care: A qualitative study.

Bayliss, Kerin, Riste, Lisa, Band, Rebecca et al.·BMC family practice·2016

This study looked at whether special training and information resources for GPs could help them better diagnose and manage ME/CFS. Researchers interviewed patients and doctors in North West England and found that while the resources were helpful when used properly, most GPs didn't actually use them—either because they were too busy, didn't see enough ME/CFS patients to remember the training, or thought the condition should only be managed by specialists.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Fibromyalgia: A Critical and Comprehensive Review.

Borchers, Andrea T, Gershwin, M Eric·Clinical reviews in allergy & immunology·2015

Fibromyalgia is a condition that causes widespread pain, fatigue, and sleep problems, and it shares many symptoms with other conditions that are hard to diagnose. This review explains that while some people think fibromyalgia might be caused by infection, inflammation, or injury, there is not strong evidence supporting these ideas. The authors recommend that treatment should focus on education, exercise, physical therapy, and approved medications rather than opioids.

Pain and SensitizationSleepDiagnostics

E3 PreliminaryReviewPEM unclearReview-Narrative

Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness.

Military medicine·2015

This review article examines how ME/CFS is currently defined and proposes that our understanding of the illness needs to be updated. The authors, writing in a military medicine context, suggest that the condition extends beyond what the traditional name 'Myalgic Encephalomyelitis/Chronic Fatigue Syndrome' captures. The paper calls for a broader perspective on how this serious illness should be recognized and understood.

E3 PreliminaryCommentaryPEM unclearEditorial

Fibromyalgia and chronic fatigue syndrome: management issues.

Bourke, Julius·Advances in psychosomatic medicine·2015

This article discusses how fibromyalgia and ME/CFS are common conditions that were previously dismissed or not taken seriously by doctors, causing patients significant suffering. Recent scientific discoveries have improved our understanding of how these conditions work in the body and what treatments may help. While complete recovery is not common, moderate improvements in symptoms and quality of life are achievable with proper management.

E3 PreliminaryDiagnosticPEM not requiredCross-Sectional

Complications in operationalizing lifelong fatigue as an exclusionary criterion.

Sunnquist, Madison, Jason, Leonard A, Brown, Abigail et al.·Journal of prevention & intervention in the community·2015

This study looked at whether people who have felt tired their whole lives should be excluded from ME/CFS diagnoses. Researchers asked patients detailed questions about lifelong fatigue and found it was very difficult to determine who truly had it. Importantly, people with and without lifelong fatigue had similar ME/CFS symptoms, suggesting this exclusion rule may not be helpful.

E3 PreliminaryDiagnosticPEM unclearMethods-Paper

An overview of operationalizing criteria for ME, ME/CFS, and CFS case definitions.

Jason, Leonard A, So, Suzanna, Evans, Meredyth et al.·Journal of prevention & intervention in the community·2015

This study looks at how researchers define and identify ME/CFS using different sets of criteria. The researchers examined various diagnostic guidelines to understand how they work in practice and what makes a good case definition. This work helps ensure that when doctors diagnose ME/CFS, they're using clear, consistent standards.

E3 PreliminaryCohortPEM not requiredCase-Control

Mitochondrial Myopathy in Follow-up of a Patient With Chronic Fatigue Syndrome.

Galán, Fernando, de Lavera, Isabel, Cotán, David et al.·Journal of investigative medicine high impact case reports·2015

This case study describes a patient who was initially diagnosed with chronic fatigue syndrome (CFS) but was later found to have a different condition called mitochondrial myopathy—a disease affecting the energy-producing structures in muscle cells. Testing showed the patient had severe deficiencies in certain components of these energy-producing structures, and genetic analysis revealed mutations inherited from the mother. The patient and family members improved significantly with high-dose vitamins B1 and B2.

E3 PreliminaryDiagnosticPEM unclearMethods-Paper

Test-Retest Reliability of the DePaul Symptom Questionnaire.

Jason, Leonard A, So, Suzanna, Brown, Abigail A et al.·Fatigue : biomedicine, health & behavior·2015

Researchers tested whether the DePaul Symptom Questionnaire (DSQ)—a tool designed to help doctors diagnose ME/CFS—gives consistent results when used multiple times. They asked 26 people with ME/CFS and 25 healthy people to answer the same questions at different times. The questionnaire proved reliable, meaning patients' answers were consistent, making it a trustworthy tool for identifying who has ME/CFS.

E3 PreliminaryReviewPEM unclearReview-Narrative

Medical constructions of long-term exhaustion, past and present.

Lian, Olaug S, Bondevik, Hilde·Sociology of health & illness·2015

This study looked at how doctors have understood exhaustion illnesses over time, comparing medical writings from 1860-1930 with those from 1970-2013. Researchers found that how these conditions were described and who had them changed dramatically: what was once seen as a physical disease affecting high-status men became viewed as a mental health problem affecting mostly women. The authors suggest these changes reflect cultural beliefs and values of each era, not just scientific discovery.

E3 PreliminaryCohortPEM not requiredCross-Sectional

Adolescents and mothers value referral to a specialist service for chronic fatigue syndrome or myalgic encephalopathy (CFS/ME).

Beasant, Lucy, Mills, Nicola, Crawley, Esther·Primary health care research & development·2014

This study asked 13 mothers and 12 teenagers with ME/CFS about their experiences getting help from a specialist ME/CFS service. Most families found it difficult and took a long time to access the specialist clinic, but once they got there, both teenagers and mothers felt it was valuable. The specialist service helped confirm the diagnosis, improved symptom management, and helped communication between doctors and schools.

InterventionsDiagnostics

E3 PreliminaryReviewPEM not requiredReview-Narrative

Chronic Fatigue Syndrome: Case Definitions and Diagnostic Assessment.

Williams, Yolonda J, Jantke, Rachel L, Jason, Leonard A·New York State psychologist·2014

This article explains why doctors have difficulty diagnosing ME/CFS and why patients often struggle to get proper care. The researchers found that there are disagreements about how to define and diagnose the illness, which makes it harder for healthcare providers to recognize it and treat it correctly. They call for better education of doctors and clearer diagnostic guidelines.

E3 PreliminaryReviewPEM unclearReview-Narrative

What is called symptom?

Eriksen, Thor Eirik, Risør, Mette Bech·Medicine, health care, and philosophy·2014

This paper explores what we actually mean by the word 'symptom' in medicine. The authors argue that when doctors can't find a clear medical cause for illness—like ME/CFS—our usual way of thinking about symptoms breaks down. They suggest we need to understand symptoms in broader ways, including how patients' social lives, personal experiences, and individual circumstances shape how they experience illness.

E3 PreliminaryCohortPEM not requiredCase-Control

Epstein-barr virus infection masquerading as acute leukemia: a report of two cases and review of literature.

Chhabra, Puneet, Law, Arjun Dutt, Sharma, Upender et al.·Indian journal of hematology & blood transfusion : an official journal of Indian Society of Hematology and Blood Transfusion·2014

This study describes two cases where patients were initially thought to have acute leukemia based on blood tests, but they actually had Epstein-Barr virus (EBV) infections instead. One patient had infectious mononucleosis, and the other had a rare EBV-related immune condition. The study shows that EBV can sometimes look like leukemia under a microscope, which can lead to misdiagnosis.

E3 PreliminaryCohortPEM not requiredObservational

Diagnosing Chronic Fatigue Syndrome in South Asians: Lessons from a Secondary Analysis of a UK Qualitative Study.

De Silva, R Erandie Ediriweera, Bayliss, Kerin, Riste, Lisa et al.·Journal of family medicine and primary care·2013

This study looked at why ME/CFS is rarely diagnosed in South Asia, even though people there experience its symptoms. By interviewing South Asian patients, doctors, and community leaders in the UK, researchers found that cultural beliefs, language barriers, and doctors' lack of knowledge about ME/CFS make it harder for people to get a proper diagnosis. The study suggests that raising awareness about ME/CFS in South Asia could help more people get diagnosed and treated.

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PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Curated Collections

Thematic groupings by clinical question or research area.

Neuroinflammation Evidence

PET imaging and other studies providing evidence for brain inflammation in ME/CFS.

Metabolism & Mitochondria

Metabolomics and mitochondrial function studies revealing energy metabolism disruption.

Biomarkers

Studies identifying potential biological markers for ME/CFS diagnosis and stratification.

PEM-Specific Research

Studies specifically examining post-exertional malaise, the hallmark symptom of ME/CFS.