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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 6,167 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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517 studies

E0 — Consensus643E1 — Replicated320E2 — Moderate2,782E3 — Preliminary2,422

ME/CFS4,025Long COVID217Post-infectious189Overlapping1,050

Required for diagnosis414Not specified / unclear2,219Not required3,534

Post-Exertional Malaise1,064Cognitive Dysfunction1,735Pain1,620Unrefreshing Sleep799Orthostatic Intolerance478

Cytokines818Gene Expression567Metabolomics473Neuroimaging468Autoantibodies458

Infection-Triggered1,174Long COVID Overlap588Pediatric493Severe231

Strong Phenotyping438Sex-Stratified326Severe ME Included118

Systematic Review265Meta-Analysis60RCT300

Peer-reviewed6,110Preprint3Unclear54

241–260 of 517 studies

E2 ModerateCohortPEM unclearObservational

'Too tired to go to the support group': a health needs assessment of myalgic encephalomyelitis.

Sutton, G C·Journal of public health medicine·1996

This 1996 study examined what healthcare services people with ME actually need in one English region. Researchers found that ME patients wanted four main things: a clear medical diagnosis, time to rest, specific treatments, and social support. However, the study found that there was no agreement among doctors and experts about what ME is, making it very difficult for the health system to plan appropriate care.

E2 ModerateCohortPEM not requiredCross-Sectional

Chronic fatigue complaints in primary care: incidence and diagnostic patterns.

Ward, M H, DeLisle, H, Shores, J H et al.·The Journal of the American Osteopathic Association·1996

This study looked at how doctors in a primary care clinic evaluate patients who complain of chronic fatigue. Researchers reviewed 425 patient charts and found that when patients mentioned chronic fatigue, doctors often did not perform complete evaluations—skipping important tests, mental health screening, and sleep history questions. Most doctors diagnosed patients with depression or general fatigue rather than investigating the chronic fatigue complaint thoroughly.

E2 ModerateCohortPEM not requiredObservational

Diagnosis in chronic illness: disabling or enabling--the case of chronic fatigue syndrome.

Woodward, R V, Broom, D H, Legge, D G·Journal of the Royal Society of Medicine·1995

This study looked at whether giving someone a CFS diagnosis helps or hurts them. Researchers interviewed 20 doctors and 50 CFS patients over 2 years. Most doctors were reluctant to diagnose CFS because they worried it might make patients feel worse, but patients actually found the diagnosis helpful because it finally explained what was wrong with them.

E2 ModerateBehavioralPEM not requiredLongitudinal

Neuraesthenia revisited: ICD-10 and DSM-III-R psychiatric syndromes in chronic fatigue patients and comparison subjects.

Farmer, A, Jones, I, Hillier, J et al.·The British journal of psychiatry : the journal of mental science·1995

This study examined psychiatric conditions in people with chronic fatigue syndrome (CFS) using standardized diagnostic interviews. Most CFS patients met criteria for a condition called neuraesthenia (an older term for nerve exhaustion) and had higher rates of depression, anxiety, and sleep problems compared to healthy people. Interestingly, when researchers followed patients over about 11 months without giving specific treatment, some psychiatric symptoms improved on their own, while the core fatigue condition remained.

SleepDiagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

Estimating rates of chronic fatigue syndrome from a community-based sample: a pilot study.

Jason, L A, Taylor, R, Wagner, L et al.·American journal of community psychology·1995

This study looked at how many people in the general community have ME/CFS by calling over 1,000 randomly selected households by telephone. Instead of relying on patients referred by doctors (which may miss people who can't afford care or distrust doctors), the researchers directly asked community members about their symptoms. They found that ME/CFS may be more common than previously thought, affecting about 0.2% of the population.

E2 ModerateCohortPEM not requiredObservational

Chronic fatigue and the chronic fatigue syndrome: prevalence in a Pacific Northwest health care system.

Buchwald, D, Umali, P, Umali, J et al.·Annals of internal medicine·1995

This study surveyed over 3,000 people in a Seattle health plan to find out how common ME/CFS and chronic fatigue are in the community. Researchers found that about 19% of people reported chronic fatigue, but only a tiny fraction actually met the strict diagnostic criteria for ME/CFS. Those with ME/CFS or chronic fatigue had worse physical health, more difficulty with daily activities, and more emotional stress compared to healthy people without fatigue.

E2 ModerateBehavioralPEM unclearObservational

Can the chronic fatigue syndrome be defined by distinct clinical features?

Hickie, I, Lloyd, A, Hadzi-Pavlovic, D et al.·Psychological medicine·1995

This study examined whether all people diagnosed with ME/CFS have the same illness or whether they actually have different types. Researchers analyzed symptoms from 565 patients and found that ME/CFS is not one uniform condition—instead, they identified two distinct patient groups with different symptom patterns, illness duration, and recovery rates.

E2 ModerateCohortPEM unclearCross-Sectional

General practitioners' attitudes to patients with a self diagnosis of myalgic encephalomyelitis.

Scott, S, Deary, I, Pelosi, A J·BMJ (Clinical research ed.)·1995

This study looked at what general practitioners (GPs) think about patients who diagnose themselves with ME/CFS. Researchers surveyed GPs in Scotland to understand their attitudes toward self-diagnosed ME/CFS patients. The findings revealed important gaps between patient experiences and how some doctors view the condition.

E2 ModerateBehavioralPEM not requiredCross-Sectional

[Epidemiologic study of chronic fatigue in primary care (general practice)].

Mann, A H, Mc Donald, E, Cope, H et al.·L'Encephale·1994

Researchers studied fatigue in patients visiting regular doctors' offices to understand how common it is and what causes it. They found that some patients had long-lasting, disabling fatigue, but these patients were very different from each other in why they thought they were tired. Most of these patients also had depression or other mental health conditions alongside their fatigue.

E2 ModerateCohortPEM unclearCross-Sectional

Comparison of patients with chronic fatigue syndrome, fibromyalgia, and multiple chemical sensitivities.

Buchwald, D, Garrity, D·Archives of internal medicine·1994

This study compared 90 patients with three conditions that cause fatigue and other symptoms: ME/CFS, fibromyalgia, and multiple chemical sensitivities. The researchers found that these three conditions are very similar in many ways—patients often report overlapping symptoms, and many people meet the criteria for more than one condition. All three groups used a lot of healthcare services, visiting doctors about 22-40 times per year on average.

E2 ModerateCohortPEM not requiredCross-Sectional

Prevalence of chronic fatigue syndrome in Italian patients with persistent fatigue.

Conti, F, Priori, R, De Petrillo, G et al.·Annali italiani di medicina interna : organo ufficiale della Societa italiana di medicina interna·1994

Researchers in Rome studied 63 patients with persistent fatigue lasting at least 6 months to see how many actually had ME/CFS. They found that only 6 patients (about 10%) met the official diagnostic criteria for ME/CFS, while 37 patients (59%) had other medical conditions explaining their fatigue, such as infections or other illnesses. This suggests that ME/CFS is relatively uncommon as a cause of severe fatigue compared to other treatable conditions.

E2 ModerateCohortPEM not requiredCross-Sectional

A comparison of case definitions of chronic fatigue syndrome.

Bates, D W, Buchwald, D, Lee, J et al.·Clinical infectious diseases : an official publication of the Infectious Diseases Society of America·1994

This study tested whether three different sets of diagnostic criteria for ME/CFS identified the same patients. Researchers looked at 805 patients at two clinics and found that about 55-61% met each of the three definitions, though different patients sometimes qualified under different criteria. The study suggests that using broader, more flexible definitions might better capture people with ME/CFS.

E2 ModerateCohortPEM not requiredCross-Sectional

Prevalence of chronic fatigue syndrome-related symptoms among nurses.

Jason, L A, Taylor, S L, Johnson, S et al.·Evaluation & the health professions·1993

This study looked at how common ME/CFS-related symptoms are among nurses. Researchers surveyed a group of nurses and found that when using different definitions of the illness, more nurses showed signs of ME/CFS than had been found in previous studies of the general population. This was the first study to specifically examine ME/CFS in healthcare workers.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue and chronic fatigue syndrome: clinical epidemiology and aetiological classification.

Manu, P, Lane, T J, Matthews, D A·Ciba Foundation symposium·1993

This study looked at 405 patients who came to a hospital complaining of chronic fatigue and tried to figure out what was causing it. Doctors found that most patients had psychiatric conditions like depression or anxiety rather than physical diseases. About 30% of patients met the definition for ME/CFS, and these patients were more likely to attribute their illness to a viral infection than other fatigued patients.

E2 ModerateCohortPEM not requiredCase-Control

A controlled study of brain magnetic resonance imaging in patients with the chronic fatigue syndrome.

Natelson, B H, Cohen, J M, Brassloff, I et al.·Journal of the neurological sciences·1993

Researchers compared brain scans (MRIs) of 52 people with ME/CFS to 52 similar healthy people. They found that ME/CFS patients were much more likely to have abnormal brain scans—27% compared to only 2% in the control group. The abnormalities included areas of white matter changes and some brain tissue enlargement, though the researchers noted that some of these findings might actually indicate other medical conditions rather than ME/CFS itself.

E2 ModerateCohortPEM not requiredCross-Sectional

Prevalence of fatigue and chronic fatigue syndrome in a primary care practice.

Bates, D W, Schmitt, W, Buchwald, D et al.·Archives of internal medicine·1993

This study looked at how common severe, long-lasting fatigue is in a primary care doctor's office and how often it is ME/CFS. Researchers found that while about 27% of patients had long-term fatigue affecting their daily life, most could be explained by other medical or mental health conditions. Only about 0.3% to 1% of patients actually had ME/CFS, depending on which diagnostic criteria were used.

E2 ModerateCohortPEM not requiredObservational

Epidemiology of chronic fatigue syndrome: the Centers for Disease Control Study.

Gunn, W J, Connell, D B, Randall, B·Ciba Foundation symposium·1993

Between 1989 and 1991, the CDC tracked patients with chronic fatigue syndrome across four U.S. cities to understand how common the illness is and who gets it. Researchers found that only about 1 in 4 patients referred to them actually met the strict diagnostic criteria for CFS, while others had different medical conditions or psychiatric histories that might explain their fatigue. The study estimated that CFS affects roughly 2–11 people per 100,000 in the general population, and it most commonly affected women in their 30s.

E2 ModerateCohortPEM unclearCross-Sectional

The overdiagnosis of Lyme disease.

Steere, A C, Taylor, E, McHugh, G L et al.·JAMA·1993

This study looked at 788 people referred to a Lyme disease clinic who were thought to have Lyme disease. Researchers found that only 23% actually had active Lyme disease, while 57% did not have Lyme disease at all—many of these patients had chronic fatigue syndrome or fibromyalgia instead. The main problem was that patients were being incorrectly diagnosed with Lyme disease and given antibiotics that didn't help because they didn't actually have the infection.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue syndrome criteria. A critique of the requirement for multiple physical complaints.

Katon, W, Russo, J·Archives of internal medicine·1992

This study looked at 285 people with chronic fatigue to understand whether having many physical symptoms was linked to psychiatric conditions like depression and anxiety. Researchers found that patients reporting more unexplained physical symptoms were significantly more likely to have current or past psychiatric diagnoses. The authors suggest that ME/CFS diagnostic criteria should be changed to include people with fatigue and few physical symptoms, and potentially exclude those with many physical complaints.

E2 ModerateCohortPEM not requiredCross-Sectional

Estimating the prevalence of chronic fatigue syndrome and associated symptoms in the community.

Price, R K, North, C S, Wessely, S et al.·Public health reports (Washington, D.C. : 1974)·1992

This study looked at how common chronic fatigue syndrome (CFS) is in the general population by surveying over 13,500 people between 1981 and 1984. Researchers found that while about 23% of people reported experiencing persistent fatigue at some point in their lives, actual CFS meeting strict diagnostic criteria was extremely rare—only 1 person in the entire study group had the condition. When researchers excluded people with other medical or psychiatric illnesses, CFS became even rarer.

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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.