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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 6,166 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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516 studies

E0 — Consensus643E1 — Replicated320E2 — Moderate2,781E3 — Preliminary2,422

ME/CFS4,025Long COVID216Post-infectious189Overlapping1,050

Required for diagnosis414Not specified / unclear2,218Not required3,534

Post-Exertional Malaise1,063Cognitive Dysfunction1,735Pain1,620Unrefreshing Sleep799Orthostatic Intolerance478

Cytokines818Gene Expression567Metabolomics473Neuroimaging468Autoantibodies458

Infection-Triggered1,174Long COVID Overlap587Pediatric493Severe231

Strong Phenotyping438Sex-Stratified326Severe ME Included118

Systematic Review265Meta-Analysis60RCT300

Peer-reviewed6,109Preprint3Unclear54

21–40 of 516 studies

E0 ConsensusReviewPEM not requiredSystematic-Review

Systematic review and meta-analysis of the prevalence of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME).

Lim, Eun-Jin, Ahn, Yo-Chan, Jang, Eun-Su et al.·Journal of translational medicine·2020

This study looked at 45 research projects involving over 1 million people to estimate how many people have ME/CFS worldwide. The researchers found that about 0.68% of the general population (roughly 1 in 150 people) has ME/CFS, though the number varies depending on who was studied and how the diagnosis was made. Women are about 1.5 to 2 times more likely to have ME/CFS than men.

E0 ConsensusReviewPEM unclearReview-Narrative

How have selection bias and disease misclassification undermined the validity of myalgic encephalomyelitis/chronic fatigue syndrome studies?

Nacul, Luis, Lacerda, Eliana M, Kingdon, Caroline C et al.·Journal of health psychology·2019

This study examines why ME/CFS research has been inconsistent and controversial. The main problem is that doctors and researchers use different definitions to diagnose ME/CFS, which means different groups of patients are studied in different research projects. The authors explain how using clearer, more consistent diagnostic criteria could help researchers better understand the disease and make progress in finding treatments.

E0 ConsensusReviewPEM unclearReview-Narrative

Myalgic encephalomyelitis/chronic fatigue syndrome and the biopsychosocial model: a review of patient harm and distress in the medical encounter.

Geraghty, Keith J, Blease, Charlotte·Disability and rehabilitation·2019

This review examines why many ME/CFS patients feel harmed or upset after seeing doctors. The researchers found seven main problems: difficulty getting diagnosed, being misdiagnosed with other conditions, trouble accessing medical support, poor quality of care, negative experiences with treatments like cognitive behavioral therapy and exercise programs, doctors not believing patients' descriptions of their illness, and emotional distress. The authors suggest that doctors should listen more carefully to patients and adopt approaches centered on what patients actually experience.

E0 ConsensusReviewPEM unclearReview-Narrative

Practical management of chronic fatigue syndrome or myalgic encephalomyelitis in childhood.

Brigden, Amberly, Loades, Maria, Abbott, Anna et al.·Archives of disease in childhood·2017

This article provides practical guidance on how doctors should diagnose and treat ME/CFS in children and teenagers. ME/CFS is a serious condition that affects at least 1 in 100 secondary school students in the UK, causing severe fatigue and limiting daily activities. Although effective treatments exist, many young people with ME/CFS don't get diagnosed or receive help they need.

E0 ConsensusReviewPEM not requiredEditorial

[Chronic Fatigue Syndrome: A Critical Review].

Rollnik, Jens D·Fortschritte der Neurologie-Psychiatrie·2017

This review examines whether ME/CFS is a distinct disease or if its symptoms overlap significantly with depression and other conditions. The authors found that while ME/CFS affects less than 1% of the population, there is no clear biological explanation for what causes it, and there are no universally agreed-upon diagnostic criteria. They recommend trying exercise, antidepressants, and talk therapy, but caution against using aggressive immune therapies without stronger evidence.

E0 ConsensusReviewPEM not requiredSystematic-Review

The differential diagnosis of tiredness: a systematic review.

Stadje, Rebekka, Dornieden, Katharina, Baum, Erika et al.·BMC family practice·2016

This study reviewed 26 previous research studies about why people feel tired when they visit their doctor. The researchers found that serious physical diseases are actually quite rare in tired patients—only about 4% have a serious organic condition. Depression was much more common, affecting about 18% of people who complain of tiredness. The main message is that doctors should focus on checking for depression and emotional stress rather than ordering extensive tests for serious diseases in most cases.

E0 ConsensusReviewPEM requiredSystematic-Review

Diagnostic Methods for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review for a National Institutes of Health Pathways to Prevention Workshop.

Haney, Elizabeth, Smith, M E Beth, McDonagh, Marian et al.·Annals of internal medicine·2015

This study reviewed 44 existing research papers to understand how doctors diagnose ME/CFS. Researchers found that doctors currently use nine different sets of diagnostic guidelines, and a new one was recently proposed by the Institute of Medicine. However, none of these methods have been properly tested to reliably identify ME/CFS patients in real-world situations where doctors are uncertain about the diagnosis.

E0 ConsensusGuidelinePEM requiredGuideline

Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness

Institute of Medicine Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome·National Academies Press·2015

The US Institute of Medicine reviewed over 9,000 scientific articles to establish new diagnostic criteria for ME/CFS. The report introduced SEID (Systemic Exertion Intolerance Disease) as a proposed name and established that ME/CFS is a serious, chronic, complex systemic disease. New criteria require PEM, unrefreshing sleep, plus cognitive impairment or orthostatic intolerance.

DiagnosticsPost-Exertional Malaise

E0 ConsensusReviewPEM unclearEvidence-Map

National Institutes of Health Pathways to Prevention Workshop: Advancing the Research on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Green, Carmen R, Cowan, Penney, Elk, Ronit et al.·Annals of internal medicine·2015

In 2015, the National Institutes of Health organized a major workshop bringing together experts to review what scientists know about ME/CFS and identify the most important questions that still need answers. The experts reviewed existing research evidence, listened to presentations, and considered feedback from patients and the public to create a roadmap for future research studies. This effort helped the U.S. medical and research community agree on which ME/CFS research areas should receive priority and funding.

E0 ConsensusReviewPEM not requiredSystematic-Review

Case definitions for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME): a systematic review.

Brurberg, Kjetil Gundro, Fønhus, Marita Sporstøl, Larun, Lillebeth et al.·BMJ open·2014

This study reviewed 20 different definitions doctors use to diagnose ME/CFS and examined 38 research studies that tested how well these definitions work. The researchers found that while one definition (CDC-1994/Fukuda) is used most often, no single definition has been proven to be the best. The study suggests that instead of creating more new definitions, doctors should focus on using the same definitions consistently and grouping patients by symptom patterns to predict who will improve with different treatments.

E0 ConsensusReviewPEM not requiredSystematic-Review

[A literature review on Chinese medicine syndrome and syndrome elements of chronic fatigue syndrome].

Peng, Min, Ma, Hong-bo, Si, Guo-min·Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine·2014

This study reviewed 20 years of Chinese medicine research on ME/CFS to identify common patterns doctors observe in patients. Researchers found that ME/CFS patients typically show patterns the Chinese medicine tradition calls 'deficiency syndromes'—meaning the body's energy (qi) and vital resources are depleted—sometimes mixed with blockages or stagnation. The most common patterns involved the spleen, liver, kidneys, and heart systems.

E0 ConsensusReviewPEM unclearSystematic-Review

Overcoming the barriers to the diagnosis and management of chronic fatigue syndrome/ME in primary care: a meta synthesis of qualitative studies.

Bayliss, Kerin, Goodall, Mark, Chisholm, Anna et al.·BMC family practice·2014

This study looked at 21 previous research articles about why many doctors struggle to diagnose and treat ME/CFS in general practice. The main problem found was that many doctors don't fully understand the condition and rely too much on traditional medical thinking that looks for single physical causes. Doctors who successfully diagnosed and managed ME/CFS patients tended to take a wider view of the illness and worked together with patients to find management strategies that worked for them.

E0 ConsensusReviewPEM unclearReview-Narrative

Is chronic fatigue syndrome the same illness as fibromyalgia: evaluating the 'single syndrome' hypothesis.

Abbi, B, Natelson, B H·QJM : monthly journal of the Association of Physicians·2013

This study looked at whether ME/CFS and fibromyalgia are actually the same illness or two different conditions. Researchers reviewed published studies comparing these two syndromes and found meaningful differences between them, suggesting they are distinct illnesses rather than just variations of one condition. This finding helps doctors understand that these are separate health problems that may need different approaches to treatment.

E0 ConsensusReviewPEM requiredSystematic-Review

The adoption of chronic fatigue syndrome/myalgic encephalomyelitis case definitions to assess prevalence: a systematic review.

Johnston, Samantha, Brenu, Ekua W, Staines, Donald R et al.·Annals of epidemiology·2013

This study looked at 31 different research projects that tried to measure how many people have ME/CFS, and found that scientists were using 8 different sets of diagnostic criteria (rules for identifying the illness). The 1994 CDC criteria became the most commonly used worldwide, but the authors argue that newer, more precise diagnostic standards like the Canadian Consensus Criteria and International Consensus Criteria should be used instead to get more accurate prevalence numbers.

E0 ConsensusReviewPEM not requiredMeta-Analysis

The prevalence of chronic fatigue syndrome/ myalgic encephalomyelitis: a meta-analysis.

Johnston, Samantha, Brenu, Ekua W, Staines, Donald et al.·Clinical epidemiology·2013

This study looked at 14 different research studies to understand how many people have ME/CFS. The researchers found that when people reported their own symptoms, about 3.3% said they had ME/CFS, but when doctors clinically assessed patients, only about 0.76% were diagnosed. This big difference suggests that how doctors test for and diagnose ME/CFS matters a lot.

E0 ConsensusReviewPEM unclearReview-Narrative

Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Jason, Leonard A, Barker, Kristen, Brown, Abigail·Reviews in health care·2012

This review examines how ME/CFS affects children and teenagers, which can be quite different from how it affects adults. The authors looked at existing research on how common pediatric ME/CFS is, how doctors diagnose it, what treatments are available, and what happens to children over time. They identified important gaps in our understanding and call for better ways to recognize and help young people with this condition.

E0 ConsensusReviewPEM not requiredReview-Narrative

A review of the definitional criteria for chronic fatigue syndrome.

Christley, Yvonne, Duffy, Tim, Martin, Colin R·Journal of evaluation in clinical practice·2012

Doctors have been trying to agree on how to diagnose ME/CFS for over 30 years, but they still don't have a single agreed-upon definition. This review looked at five different official definitions that doctors use to diagnose the condition. The most commonly used definition, from the CDC in 1994, has never been proven to be better than the others and has been criticized for not being specific enough.

E0 ConsensusReviewPEM not requiredReview-Narrative

CFS: A Review of Epidemiology and Natural History Studies.

Jason, Leonard A, Porter, Nicole, Brown, Molly et al.·Bulletin of the IACFS/ME·2009

Most ME/CFS research has only studied patients who went to doctors or hospitals, which misses people from minority communities and lower-income backgrounds who may not have access to medical care. This review looks at what we know about how common ME/CFS is, how it develops, and what factors increase the risk of getting it. The authors highlight one study that looked at ME/CFS in a diverse urban community rather than just in clinic patients, which gives a more accurate picture of the illness.

E0 ConsensusReviewPEM not requiredSystematic-Review

A systematic review of chronic fatigue syndrome: don't assume it's depression.

Griffith, James P, Zarrouf, Fahd A·Primary care companion to the Journal of clinical psychiatry·2008

This review examined how ME/CFS is different from depression, since doctors often confuse the two conditions. The researchers looked at hundreds of medical articles to understand what causes ME/CFS, how to properly diagnose it, and how to treat it. They found that ME/CFS is missed in over 80% of people who have it, and is frequently wrongly labeled as depression instead.

E0 ConsensusGuidelinePEM requiredGuideline

Diagnosis and management of chronic fatigue syndrome or myalgic encephalomyelitis (or encephalopathy): summary of NICE guidance.

Baker, R, Shaw, E J·BMJ (Clinical research ed.)·2007

This document summarizes official guidance from NICE (the UK's National Institute for Health and Care Excellence) on how to diagnose and manage ME/CFS. It provides recommendations for healthcare professionals on recognizing the condition, running appropriate tests, and treating patients with practical advice on activity management, rehabilitation, and when to refer patients to specialists.

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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.