ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

2768 studies

41–60 of 2,768 studies

E2 ModerateCohortPEM unclearCross-Sectional

Underuse of Pharmacologic Therapies for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Before Specialist Evaluation.

Grach, Stephanie L, Seltzer, Jaime, Mueller, Michael R et al.·Annals of family medicine·2026

A study of 571 ME/CFS patients in Minnesota found that about two-thirds had tried at least one medication before seeing a specialist, and over 70% had used dietary supplements. The researchers observed that medications commonly recommended by ME/CFS specialists—such as certain antidepressants and gabapentin—appear to be prescribed less often by general doctors compared to pain and anxiety medications. It remains unclear whether this pattern reflects clinical caution, lack of awareness, or other factors in primary care practice.

Interventions

E2 ModerateCohortPEM unclearCross-Sectional

Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome.

Azcue, N, Prada, A, Del Pino, R et al.·Scientific reports·2026

Researchers compared immune markers called autoantibodies in people with post-COVID condition, ME/CFS, and healthy controls. They found that people with ME/CFS had higher levels of antibodies against certain nerve receptors (β2 adrenergic), and these antibodies were associated with autonomic nervous system problems and memory changes. However, this is a single cross-sectional study, and autoimmunity remains one of several proposed mechanisms—it is not yet clear whether these antibodies are a cause or a consequence of ME/CFS.

BiomarkersAutonomic Nervous SystemImmune SystemCognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Ocular Symptoms in Long COVID: A Cross-Sectional Study.

Kaleem, Shayaan, Sawano, Mitsuaki, Arun, Adith S et al.·Clinical ophthalmology (Auckland, N.Z.)·2026

This study looked at eye problems in people with long COVID, comparing those who developed new eye symptoms (like blurred vision, dry eyes, or floaters) after infection with those who didn't. About 57% of the 595 participants reported new eye symptoms. People with eye symptoms had worse overall health, more financial struggles, and were more likely to have dysautonomia (problems with blood pressure and heart rate control) and ME/CFS.

Autonomic Nervous System

E2 ModerateCohortPEM unclearCross-Sectional

3D Virtual Reality Performance Metrics as a Future Fatigue Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Ladek, Anja-Maria, Priebe, Leonie, Harrer, Thomas et al.·Biomedicines·2026

Researchers tested how quickly 60 ME/CFS patients and 60 healthy controls could react to visual tasks presented in 3D virtual reality. ME/CFS patients showed slower reaction times across all difficulty levels, and they improved less with practice than controls did. The study reports an association between ME/CFS and prolonged reaction times, though the findings are preliminary and whether this could become a reliable test for fatigue severity requires further validation.

BiomarkersDiagnosticsCognitive Impairment

E2 ModerateCohortPEM requiredCross-Sectional

Impact of post-exertional malaise frequency and fatigue in Long COVID patients on health-related quality of life.

Thölking, Theresa, Müller, Frank, Riester, Tim et al.·Health and quality of life outcomes·2026

This study surveyed German adults with Long COVID and post-exertional malaise (PEM) to understand how the frequency and severity of PEM relates to quality of life. Researchers found that people reporting more frequent and more severe PEM were associated with lower quality-of-life scores, even after accounting for age, sex, and employment status. These are preliminary findings from a single survey and do not establish that PEM causes poor quality of life, but rather that the two observations occurred together in this group.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCase-Control

Interpreting hand grip strength in hospital employees with post-COVID syndrome compared to non-infected controls: a case-control study.

Tack, Matthias, Gruber, Rosalie, Betting, Leia et al.·Scientific reports·2026

This small study compared hand grip strength in 19 hospital workers with post-COVID syndrome (including 7 who met ME/CFS criteria) to 23 healthy controls. Researchers found that grip strength tended to be lower in the post-COVID group, particularly when tested a second time after a 60-minute break, which might suggest difficulty recovering after repeated effort. However, these are preliminary findings from a small group, and the authors note that grip strength alone is not reliable enough to diagnose post-COVID syndrome.

DiagnosticsPost-Exertional Malaise

E2 ModerateCohortPEM not requiredObservational

Shared genetic risk between functional somatic syndromes, internalizing disorders, and immune-mediated diseases: a twin-sibling study.

Steen, Olivier D, Ohlsson, Henrik, van Ockenburg, Sonja L et al.·Brain, behavior, and immunity·2026

A large Swedish study examined whether functional somatic syndromes (including ME/CFS, fibromyalgia, and IBS) and depression/anxiety share genetic risk factors with immune-mediated diseases. Researchers observed that fibromyalgia showed the strongest shared genetic risk with immune diseases, while ME/CFS showed more modest genetic overlap. The findings are preliminary and do not explain why these conditions cluster together, only that genetic factors may contribute to some shared risk.

BiomarkersImmune System

E2 ModerateCohortPEM not requiredCross-Sectional

Subclinical Hypercoagulable Viscoelastic Characteristics Associated with Post-Acute Sequelae of SARS-CoV2 Physical Symptoms in COVID-19 ALI/ARDS Survivors.

Jones, Ansley E, Mira-Sanchez, Margarita, Khan, Zain et al.·Journal of intensive care medicine·2026

This study examined blood clotting patterns in 93 people who survived severe COVID-19 requiring hospitalization, testing them 15 months after discharge. Researchers observed that those with lingering post-COVID symptoms—particularly fatigue and post-exertional malaise (worsening after activity)—showed altered clotting characteristics on specialized blood tests, specifically higher fibrinogen levels. However, this is a single cross-sectional study and does not establish whether these clotting changes cause the symptoms or are simply associated with them.

BiomarkersLong COVID Overlap

E2 ModerateCohortPEM unclearCross-Sectional

Central noradrenergic deficiency in post-infectious chronic fatigue: neurobehavioral correlates.

Aregawi, Lillian, Walitt, Brian, Sullivan, Patti et al.·Brain communications·2026

Researchers measured levels of norepinephrine (a brain chemical) in cerebrospinal fluid from people with ME/CFS, Long COVID, and Parkinson's disease, comparing them to healthy volunteers. They observed that norepinephrine pathway activity was lower in all three patient groups, and in Long COVID patients with post-exertional malaise, this reduction was particularly pronounced. This is one study in a small sample, and it remains unclear whether these findings fully explain fatigue and brain fog or apply directly to ME/CFS.

BiomarkersCognitive ImpairmentLong COVID OverlapPost-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Cardiopulmonary exercise test results do not change over two sequential days in patients with chronic fatigue syndrome.

Mancini, Donna M, Cook, Dane B, Brunjes, Danielle L et al.·Frontiers in physiology·2026

Researchers asked whether doing two exercise tests on consecutive days could reliably detect post-exertional malaise (PEM) in ME/CFS patients. They found that oxygen consumption and other key exercise measures did not change between Day 1 and Day 2 in either ME/CFS patients or healthy controls. However, ME/CFS patients reported much greater fatigue during exercise and had lower maximum heart rates. One study's findings do not establish whether this two-day test method is truly useful for measuring PEM in clinical practice.

DiagnosticsPost-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Understanding concussion in myalgic encephalomyelitis/chronic fatigue syndrome: Findings from the 2023 National Health Interview study.

Sirotiak, Zoe, Adamowicz, Jenna L, Thomas, Emily B K·Brain injury·2026

This study found that people with ME/CFS are nearly 5 times more likely to have had a concussion in the past year compared to people without ME/CFS. People with ME/CFS also experienced more falls and dizziness or balance problems. The researchers suggest that doctors should screen patients with ME/CFS more carefully for concussions and take steps to reduce their concussion risk.

Autonomic Nervous System

E2 ModerateCohortPEM requiredCross-Sectional

Distinct functional connectivity patterns in myalgic encephalomyelitis and long COVID patients during cognitive fatigue: a 7 Tesla task-fMRI study.

Inderyas, Maira, Thapaliya, Kiran, Marshall-Gradisnik, Sonya et al.·Journal of translational medicine·2026

This study used advanced brain imaging to compare how the brains of ME/CFS patients, long COVID patients, and healthy people work during a challenging thinking task. Researchers found that patients' brains show different patterns of communication between regions compared to healthy controls, particularly in areas related to motivation, memory, and emotional processing. These brain differences appeared to worsen as fatigue built up during the task.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Shared autonomic phenotype of long COVID and myalgic encephalomyelitis/chronic fatigue syndrome.

Novak, Peter, Systrom, David M, Witte, Alexandra et al.·PloS one·2026

Researchers compared people with Long COVID and ME/CFS to healthy volunteers and found they share very similar patterns of nervous system dysfunction, including problems with blood flow to the brain when standing up, widespread autonomic problems, and nerve damage in the skin. While the two conditions show these striking similarities, the study couldn't identify a single test that clearly separates them from each other, suggesting they may develop through related mechanisms.

Autonomic Nervous System

E2 ModerateCohortPEM requiredObservational

[The Role of ME/CFS Phenotype in Outpatient Post-COVID Rehabilitation].

Kaiserseder, Moritz, Prüfer, Ferdinand, Untersmayer-Elsenhuber, Eva et al.·Pneumologie (Stuttgart, Germany)·2026

This study looked at 216 people recovering from COVID-19 in rehabilitation programs to see how many had ME/CFS—a condition with severe fatigue and worsening after physical activity. The researchers found that about 7% of these patients met the criteria for ME/CFS. These patients were typically younger, mostly women, and experienced much more severe fatigue that didn't improve with rehabilitation compared to other COVID-19 patients.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

The fatigue spectrum in a community-based long haul COVID cohort.

Carter, Isabelle V, May, Anna, Hsieh, Isabella C et al.·Sleep & breathing = Schlaf & Atmung·2026

This study looked at 277 people with long COVID who visited a specialized clinic, focusing on those experiencing fatigue. About 73% reported fatigue as a main symptom, but only about 22% of those met the strict ME/CFS diagnostic criteria. The researchers found that fatigue severity varied widely, and fatigue often came alongside other symptoms like brain fog, anxiety, and reduced physical functioning.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredObservational

Postexertional Symptom Exacerbation after Submaximal Exercise in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Postacute Sequelae of COVID-19.

Berardi, Giovanni, Janowski, Adam, McNally, Samuel et al.·Medicine and science in sports and exercise·2026

This study looked at what happens when people with ME/CFS or long COVID do moderate exercise. Researchers asked 60 patients and 30 healthy people to exercise for 25 minutes, then tracked their symptoms for a week. Most patients with ME/CFS experienced worsening fatigue, mental fog, and other symptoms in the days after exercise, but the severity and which symptoms got worse varied from person to person.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearLongitudinal

Chronic Reactivation of Persistent Human Herpesviruses EBV, HHV-6 and VZV and Heightened Anti-dUTPase IgG Antibodies Are a Recurrent Hallmark in Post-Infectious ME/CFS and is Associated With Fatigue.

Palomo, Irene Mena, Cox, Brandon, Williams, Marshall V et al.·Journal of medical virology·2026

This study found that people with ME/CFS have higher levels of immune responses to three common viruses (EBV, HHV-6, and VZV) compared to healthy people. About 72% of ME/CFS patients showed antibodies to multiple viruses at the same time, versus only 31% of healthy controls. The antibody levels were higher in patients with moderate to severe fatigue, suggesting a possible connection between these viral reactivations and symptom severity.

BiomarkersImmune System

E2 ModerateCohortPEM unclearObservational

Associations between heart rate and physical activity in people with post-COVID-19 condition accounting for myalgic encephalomyelitis/chronic fatigue syndrome symptoms.

Adodo, Rachel, Sarmento Da Nobrega, Antonio, Villar, Rodrigo et al.·Journal of rehabilitation medicine·2026

This study looked at how heart rate and physical activity are related in people with long COVID who also have ME/CFS-like symptoms. Researchers found that people experienced more episodes of rapid heartbeat (over 100 beats per minute) when they were resting or doing very little, but surprisingly had fewer of these episodes during moderate-to-vigorous exercise. This suggests that the relationship between activity and heart rate in long COVID may be more complex than previously thought.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

A Description of Healthcare Utilization in Young Adults with Chronic Overlapping Pain.

Babiloni, Alberto Herrero, Brown, Courtney, Ash, Peyton et al.·The Clinical journal of pain·2026

This study looked at 50 young adults who have multiple overlapping pain conditions (including ME/CFS, fibromyalgia, and chronic back pain) to understand how much healthcare they use and whether it helps. On average, these patients saw 2-3 doctors currently and had seen 4 different doctors in the past, yet 78% said their conditions stayed the same or got worse. The findings suggest that simply seeing more doctors and taking more medications isn't enough—patients may need better-coordinated, team-based care.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Who receives a diagnostic label for fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome? A study in the lifelines cohort.

Tattan, Mais, Hanssen, Denise J C, Rosmalen, Judith G M·Journal of psychosomatic research·2026

This study looked at over 150,000 people to understand why some people with ME/CFS, fibromyalgia, or irritable bowel syndrome receive a diagnosis while others with the same symptoms do not. The researchers found that only a small number of people who meet the criteria for these conditions actually get diagnosed—about 14% for ME/CFS. Several factors like sex, education level, other health conditions, and how often people visit doctors affected whether they received a diagnosis.

Diagnostics

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Underuse of Pharmacologic Therapies for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Before Specialist Evaluation.

Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome.

Ocular Symptoms in Long COVID: A Cross-Sectional Study.

3D Virtual Reality Performance Metrics as a Future Fatigue Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Impact of post-exertional malaise frequency and fatigue in Long COVID patients on health-related quality of life.

Interpreting hand grip strength in hospital employees with post-COVID syndrome compared to non-infected controls: a case-control study.

Shared genetic risk between functional somatic syndromes, internalizing disorders, and immune-mediated diseases: a twin-sibling study.

Subclinical Hypercoagulable Viscoelastic Characteristics Associated with Post-Acute Sequelae of SARS-CoV2 Physical Symptoms in COVID-19 ALI/ARDS Survivors.

Central noradrenergic deficiency in post-infectious chronic fatigue: neurobehavioral correlates.

Cardiopulmonary exercise test results do not change over two sequential days in patients with chronic fatigue syndrome.

Understanding concussion in myalgic encephalomyelitis/chronic fatigue syndrome: Findings from the 2023 National Health Interview study.

Distinct functional connectivity patterns in myalgic encephalomyelitis and long COVID patients during cognitive fatigue: a 7 Tesla task-fMRI study.

Shared autonomic phenotype of long COVID and myalgic encephalomyelitis/chronic fatigue syndrome.

[The Role of ME/CFS Phenotype in Outpatient Post-COVID Rehabilitation].

The fatigue spectrum in a community-based long haul COVID cohort.

Postexertional Symptom Exacerbation after Submaximal Exercise in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Postacute Sequelae of COVID-19.

Chronic Reactivation of Persistent Human Herpesviruses EBV, HHV-6 and VZV and Heightened Anti-dUTPase IgG Antibodies Are a Recurrent Hallmark in Post-Infectious ME/CFS and is Associated With Fatigue.

Associations between heart rate and physical activity in people with post-COVID-19 condition accounting for myalgic encephalomyelitis/chronic fatigue syndrome symptoms.

A Description of Healthcare Utilization in Young Adults with Chronic Overlapping Pain.

Who receives a diagnostic label for fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome? A study in the lifelines cohort.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

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