ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

981–1000 of 6,187 studies

E2 ModerateCohortPEM requiredObservational

Assessment and Incidence Determination of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Following a SARS-CoV-2 Infection in a Prospective Cohort of Hospital Employees.

Tack, Matthias, Gruber, Rosalie, Betting, Leia et al.·Medicina (Kaunas, Lithuania)·2026

This study followed hospital workers who got COVID-19 to see how many developed long-lasting fatigue and ME/CFS. About 12% still had fatigue months later, and 3% met the criteria for ME/CFS. Researchers found that people with these conditions often had signs of viral reactivation, immune system changes, and blood clotting abnormalities.

Post-Exertional Malaise

E2 ModerateDiagnosticPEM unclearCross-Sectional

Improving myalgic encephalomyelitis population sampling: Applying an online respondent-driven method to address biases in G93.3 register data.

Kielland, Anne, Liu, Jing, Tyldum, Guri et al.·Journal of health psychology·2026

This study looked at how well official medical records capture ME/CFS cases and who gets diagnosed. Researchers found that medical register data misses many cases and disproportionately underrepresents people from lower-income backgrounds. They used a new online method to find ME/CFS patients more accurately and checked whether official diagnoses matched recognized diagnostic criteria.

Diagnostics

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 unclearCross-Sectional

Assessment of dynamic cerebral blood flow changes during cognitive tasks in patients with post-COVID-19 syndrome.

Kutz, Dieter F, Garbsch, René, Mooren, Frank C et al.·Brain communications·2026

This study looked at how blood flow in the brain changes when people with post-COVID-19 syndrome try to do mental tasks. Researchers used special infrared cameras to watch blood flow in the thinking part of the brain while patients did concentration exercises. They found that people with post-COVID-19 had unusual, less flexible blood flow patterns compared to healthy people, which may help explain why they feel mentally tired and have trouble concentrating.

Cognitive Impairment

E2 ModerateCohortPEM unclearCross-Sectional

Hypermethylation of OPRM1: Deregulation of the Endogenous Opioid Pathway in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia.

Wyns, Arne, Hendrix, Jolien, Van Campenhout, Jente et al.·International journal of molecular sciences·2026

This study examined whether changes in how a gene called OPRM1 (which controls opioid receptors in the body) are chemically marked in people with ME/CFS and fibromyalgia. Researchers found that people with these conditions had higher levels of these chemical marks on the OPRM1 gene compared to healthy people, even after accounting for how severe their symptoms were. This suggests that problems with the body's natural pain-relief system may be a fundamental part of these illnesses.

E2 ModerateCohortPEM not requiredCross-Sectional

Microstructural white matter impairments in chronic fatigue syndrome: Evidence of segmental injury in the cingulum bundle.

Wu, Kang, Wu, Ziyao, Feng, Sitong et al.·Brain research bulletin·2026

This study looked at brain structure in people with ME/CFS by scanning the white matter (the brain's communication highways) and comparing them to healthy people. Researchers found that people with ME/CFS had damage in specific bundles of brain fibers called the cingulum, which is involved in emotion and memory. The damage was found in particular sections of this bundle, and fixing this damage appeared linked to feeling less fatigued.

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 ModerateCohortPEM unclearCase-Control

Multi-omics identifies lipid accumulation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome cell lines: a case-control study.

Missailidis, Daniel, Armstrong, Christopher W, Anderson, Dovile et al.·Journal of translational medicine·2026

Researchers studied immune cells from people with ME/CFS and found that these cells accumulate abnormal amounts of fats (lipids) compared to healthy controls. The cells also show changes in how they process and use these fats for energy. This discovery suggests that problems with how the body handles fats might be part of what makes ME/CFS different at the cellular level.

Immune System

E2 ModerateCohortPEM not requiredLongitudinal

A longitudinal study on the correlation between symptom clusters and disease-specific health status in older adults with chronic obstructive pulmonary disease during pulmonary rehabilitation.

Yang, Jinghua, Xu, Na, Liang, Mengyao·Frontiers in public health·2026

This study followed 184 older adults with COPD (a lung disease) over 12 weeks of rehabilitation to understand how their symptoms changed and how those changes affected their quality of life. Researchers found that symptoms shifted over time—starting with breathing problems and tiredness, then developing muscle soreness and swelling with exercise, and eventually centering on fatigue and social withdrawal. The type of symptoms that most affected patients' wellbeing also changed throughout rehabilitation, suggesting that different support may be needed at different stages of recovery.

Post-Exertional Malaise

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

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 unclearCase-Control

ICD-10 Diagnoses prior to ME/CFS diagnosis in children and young people suggest potential early diagnostic indicators.

Wirth, Marielle, Haastert, Burkhard, Linnenkamp, Ute et al.·Scientific reports·2026

This study looked at medical records of young people (ages 6-27) diagnosed with ME/CFS to see what health problems they had in the year before their diagnosis. Researchers found that certain conditions—like fatigue, depression, pain disorders, and post-COVID-19 condition—appeared more often in people who later developed ME/CFS compared to similar young people who didn't develop it. This suggests these earlier diagnoses might be early warning signs or related to ME/CFS development, though the study cannot prove they actually caused ME/CFS.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Disequilibrium, Rather than Postural Orthostatic Tachycardia Syndrome, Is the Primary Determinant of Orthostatic Intolerance in Patients with Long COVID.

Miwa, Kunihisa·Journal of clinical medicine·2026

Many long COVID patients experience dizziness and difficulty standing (orthostatic intolerance), but researchers found this is not usually caused by the heart racing when standing up (POTS). Instead, balance problems detected by simple standing tests were the main cause in these patients. When treated with an antibiotic or brain stimulation therapy, most patients with balance-related standing problems improved.

Autonomic Nervous System

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

E2 ModerateCohortPEM unclearCross-Sectional

Evidence of White Matter Neuroinflammation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Diffusion-Based Neuroinflammation Imaging Study.

Yu, Qiang, Kothe, Kiana, Kwiatek, Richard A et al.·Human brain mapping·2026

This study used advanced brain imaging to look for signs of inflammation in the white matter (the brain's communication cables) of ME/CFS patients compared to healthy people. Researchers found several differences in how water moves through brain tissue in ME/CFS patients, suggesting there may be swelling, immune cell activity, and changes to nerve fibers. These imaging markers could potentially help doctors identify and track ME/CFS in the future.

Neuroinflammation

E2 ModerateCohortPEM unclearCross-Sectional

Use and Perceived Helpfulness of Different Intervention Strategies in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Depression.

Dorczok, Marie Celine, Mossaheb, Nilufar, Mittmann, Gloria et al.·Journal of clinical medicine·2026

This study compared how people with ME/CFS and depression use different treatments and how helpful they find them. People with ME/CFS tried a much wider variety of interventions—especially pacing strategies and supplements aimed at energy—and found many of them helpful. In contrast, people with depression mainly used psychotherapy and antidepressants, which align with standard medical guidelines. The difference likely reflects that ME/CFS currently lacks established treatment guidelines, while depression has well-tested approaches.

Interventions

E2 ModerateBehavioralPEM not requiredObservational

Prevalence of Bodily Distress Syndrome and Prediction of Patient Outcomes: Cohort Study of 3762 Individuals With Persistent Pain.

Landmark, Live, Sunde, Hans Fredrik, Fors, Egil A et al.·European journal of pain (London, England)·2026

This study looked at how multiple physical symptoms often occur together in people with chronic pain, using a framework called Bodily Distress Syndrome (BDS). Among 3,762 people attending a specialized pain clinic, 92.5% showed moderate to severe BDS, and those with BDS experienced more severe symptoms and psychological stress. After one year, people with BDS improved less and reported less benefit from treatment compared to those without BDS.

Pain and Sensitization

E2 ModerateCohortPEM requiredLongitudinal

Post-discharge sequelae of Lassa fever survivors in Nigeria: an analysis of the LASCOPE prospective cohort.

Guichard, Eva, Juchet, Sylvain, Etafo, Ijeoma Chukwudumebi et al.·The Lancet. Infectious diseases·2026

This study followed 882 people who recovered from Lassa fever (a serious viral infection) after hospital discharge to see what long-term symptoms they experienced. Most survivors felt better within about 3 weeks after leaving the hospital, with the most common lingering symptoms being tiredness, headaches, and difficulty with physical activity. The good news is that serious complications like hearing loss were rare, affecting only 2% of survivors.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Altered Pain Perception and Modulation in Individuals With Post-COVID-Condition: Insights From Quantitative Sensory Testing.

Lange, Hannah, Reichert, Julian, Vock, Stephanie et al.·European journal of pain (London, England)·2026

This study tested how people with long COVID perceive and respond to pain compared to healthy people. Researchers applied pressure to participants' legs and measured when they first felt pain and when pain became unbearable. People with long COVID felt pain at lower pressure levels and their pain got worse more quickly than healthy controls, suggesting their nervous systems process pain differently.

Pain and Sensitization

E2 ModerateCohortPEM unclearCross-Sectional

Extracellular Vesicle Protein and MiRNA Signatures as Biomarkers for Post-Infectious ME/CFS Patients.

Seifert, Martina, Schäfers, Johannes, Douglas, Fiona F et al.·International journal of molecular sciences·2026

Researchers examined tiny packages of proteins and molecules (called extracellular vesicles) found in the blood of ME/CFS patients to see if they contain unique signatures that could help diagnose the disease. They found that certain proteins and a specific small molecule called hsa-let-7b-5p were different in ME/CFS patients compared to healthy people, and these differences were linked to worse fatigue, pain, and immune problems. This discovery suggests that blood tests measuring these substances could eventually help doctors diagnose ME/CFS and better understand who has the disease.

Biomarkers

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Assessment and Incidence Determination of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Following a SARS-CoV-2 Infection in a Prospective Cohort of Hospital Employees.

Improving myalgic encephalomyelitis population sampling: Applying an online respondent-driven method to address biases in G93.3 register data.

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

Assessment of dynamic cerebral blood flow changes during cognitive tasks in patients with post-COVID-19 syndrome.

Hypermethylation of OPRM1: Deregulation of the Endogenous Opioid Pathway in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia.

Microstructural white matter impairments in chronic fatigue syndrome: Evidence of segmental injury in the cingulum bundle.

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

Multi-omics identifies lipid accumulation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome cell lines: a case-control study.

A longitudinal study on the correlation between symptom clusters and disease-specific health status in older adults with chronic obstructive pulmonary disease during pulmonary rehabilitation.

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

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

ICD-10 Diagnoses prior to ME/CFS diagnosis in children and young people suggest potential early diagnostic indicators.

Disequilibrium, Rather than Postural Orthostatic Tachycardia Syndrome, Is the Primary Determinant of Orthostatic Intolerance in Patients with Long COVID.

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

Evidence of White Matter Neuroinflammation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Diffusion-Based Neuroinflammation Imaging Study.

Use and Perceived Helpfulness of Different Intervention Strategies in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Depression.

Prevalence of Bodily Distress Syndrome and Prediction of Patient Outcomes: Cohort Study of 3762 Individuals With Persistent Pain.

Post-discharge sequelae of Lassa fever survivors in Nigeria: an analysis of the LASCOPE prospective cohort.

Altered Pain Perception and Modulation in Individuals With Post-COVID-Condition: Insights From Quantitative Sensory Testing.

Extracellular Vesicle Protein and MiRNA Signatures as Biomarkers for Post-Infectious ME/CFS Patients.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research