ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

281–300 of 380 studies

E2 ModerateCohortPEM not requiredCross-Sectional

Behavioural problems associated with the chronic fatigue syndrome.

Smith, A P, Behan, P O, Bell, W et al.·British journal of psychology (London, England : 1953)·1993

This study tested whether people with ME/CFS actually experience the memory, concentration, and coordination problems they report. Researchers gave 57 ME/CFS patients and 19 healthy controls a series of computerized tests measuring thinking speed, memory, attention, and motor skills. ME/CFS patients performed worse on many tests—they were slower at tasks requiring coordination, had trouble focusing, and struggled with complex reasoning—even though their depression and anxiety levels didn't fully explain these differences.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Fatigue, depression, and social adjustment in chronic fatigue syndrome.

Walford, G A, Nelson, W M, McCluskey, D R·Archives of disease in childhood·1993

This study looked at 12 children with ME/CFS and compared them to children with cystic fibrosis and healthy children. Children with ME/CFS reported much higher levels of tiredness affecting both body and mind, and many showed signs of depression. Their schooling and social lives were seriously disrupted by the illness.

Cognitive Impairment

E2 ModerateCohortPEM unclearCase-Control

Information processing efficiency in chronic fatigue syndrome and multiple sclerosis.

DeLuca, J, Johnson, S K, Natelson, B H·Archives of neurology·1993

This study compared thinking and concentration abilities in people with ME/CFS, people with multiple sclerosis (MS), and healthy volunteers. All participants were matched by age and education level. People with ME/CFS and MS both showed difficulty with tasks requiring fast, complex thinking compared to healthy controls, suggesting that ME/CFS may affect how the brain processes information.

Cognitive Impairment

E2 ModerateCohortPEM unclearCross-Sectional

Quality of attention in chronic fatigue syndrome: subjective reports of everyday attention and cognitive difficulty, and performance on tasks of focused attention.

Ray, C, Phillips, L, Weir, W R·The British journal of clinical psychology·1993

Many people with ME/CFS report problems with attention and concentration in daily life. This study compared ME/CFS patients with healthy people using questionnaires about attention problems and computer-based attention tests. Patients reported significantly more attention difficulties than controls, though standard attention tests didn't show clear differences. Interestingly, patients were slower at processing tasks like reading words and naming colors, suggesting their thinking speed may be affected rather than their ability to focus.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

A brief mental fatigue questionnaire.

Bentall, R P, Wood, G C, Marrinan, T et al.·The British journal of clinical psychology·1993

Researchers created a short questionnaire to measure mental tiredness and tested it in people with ME/CFS, depression, recovered ME/CFS, muscle disease, and healthy people. The questionnaire worked well at identifying mental fatigue, but it could not tell the difference between people with ME/CFS and people with depression—both groups reported similar types and amounts of mental tiredness.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCase-Control

Attention and short-term memory in chronic fatigue syndrome patients: an event-related potential analysis.

Scheffers, M K, Johnson, R, Grafman, J et al.·Neurology·1992

This study compared brain activity and reaction times between 13 people with ME/CFS and 13 healthy volunteers using brain scans while they performed attention and memory tasks. The ME/CFS patients showed much slower and more variable reaction times, but their memory and thinking abilities appeared normal. The researchers found that the brain's basic attention and memory processes were working similarly in both groups, suggesting the slowness came from problems with how the brain signals muscles to respond.

Cognitive Impairment

E2 ModerateBehavioralPEM not requiredCross-Sectional

Illness perception and symptom components in chronic fatigue syndrome.

Ray, C, Weir, W R, Cullen, S et al.·Journal of psychosomatic research·1992

This study asked 208 people with ME/CFS about their symptoms and how they experience their illness. Researchers found that ME/CFS involves four main types of problems: emotional distress, fatigue, physical symptoms, and difficulty thinking clearly. Emotional distress did not directly determine how sick people felt overall, but negative emotions did make the other symptoms worse.

Cognitive Impairment

E3 PreliminaryMechanismPEM unclearCross-Sectional

Reduced Adenosine Triphosphate-to-Phosphocreatine Ratios in Neuropsychiatric Post-COVID Condition: Evidence From 31P Magnetic Resonance Spectroscopy.

Weber-Fahr, Wolfgang, Dommke, Sandra, Sack, Markus et al.·Biological psychiatry·2026

This study looked at how the brain produces and uses energy in people with long COVID and cognitive problems. Using a special brain imaging scan, researchers found that people with long COVID have lower energy levels in a part of their brain called the cingulate cortex, and this energy shortage is linked to thinking and memory problems. The findings suggest that problems with how brain cells produce energy may be a key reason why some people experience cognitive difficulties after COVID-19.

Cognitive Impairment

E3 PreliminaryMechanismPEM unclearCross-Sectional

Autonomic phenotyping, brain blood flow control, and cognitive-motor-integration in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome: A pilot study.

Badhwar, Smriti, Pereira, Tania J, Kerr, Kathleen et al.·Autonomic neuroscience : basic & clinical·2025

This study compared how the nervous systems of ME/CFS patients, Long COVID patients, and healthy people respond to physical stress tests like breathing different air mixtures and tilting upright. The researchers found that ME/CFS and Long COVID patients had different patterns of problems: ME/CFS patients showed difficulty controlling blood flow to the brain during one test, which was linked to coordination problems, while Long COVID patients had lower oxygen levels when upright and their nervous systems didn't adapt as well.

Autonomic Nervous SystemCognitive Impairment

E3 PreliminaryMechanismPEM requiredPreprintPreprint

Dissecting the genetic complexity of myalgic encephalomyelitis/chronic fatigue syndrome via deep learning-powered genome analysis.

Zhang, Sai, Jahanbani, Fereshteh, Chander, Varuna et al.·medRxiv : the preprint server for health sciences·2025

Researchers used advanced artificial intelligence to analyze the genes of ME/CFS patients and discovered 115 genes that may contribute to the disease. They found that people with ME/CFS have lower levels of these risk genes active in their immune cells and nervous system. This genetic analysis could eventually help doctors diagnose ME/CFS more accurately and identify new treatment targets.

BiomarkersCognitive ImpairmentImmune System

E3 PreliminaryReviewPEM unclearReview-Narrative

[Modern approaches to diagnosis and treatment of postinfectious asthenic syndrome in children].

Nemkova, S A·Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova·2025

This review article discusses postinfectious asthenic syndrome—a condition causing severe tiredness and weakness that develops after infections like colds, flu, and COVID-19 in children and teenagers. The authors examine how this condition develops, its symptoms, and how a medication called Mexidol may help reduce fatigue and improve thinking, mood, and nervous system problems that often accompany it.

Cognitive ImpairmentAutonomic Nervous System

E3 PreliminaryCohortPEM unclearCase-Control

Improvement in Upper Limb and Systemic Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Symptoms After Surgical Treatment of Neurogenic Thoracic Outlet Syndrome.

Christoforou, Maritsa E, Lum, Ying Wei, Sroge, Sally C et al.·Cureus·2025

This case study describes a 19-year-old woman with ME/CFS who also had a condition called thoracic outlet syndrome (TOS), where nerves in the upper chest become compressed. After surgery to relieve this compression on both sides of her body, she experienced not only relief from arm numbness and tingling, but also surprising improvements in migraines, brain fog, dizziness, and vision problems. This suggests that some ME/CFS patients might benefit from being evaluated for TOS, as treating it could potentially help with multiple symptoms.

Cognitive ImpairmentAutonomic Nervous System

E3 PreliminaryMechanismPEM unclearMechanistic

Six-Week Supplementation with Creatine in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Magnetic Resonance Spectroscopy Feasibility Study at 3 Tesla.

Godlewska, Beata R, Sylvester, Amy L, Emir, Uzay E et al.·Nutrients·2024

Researchers gave 11 people with ME/CFS a creatine supplement (a natural substance that helps cells produce energy) for 6 weeks. Brain scans showed the supplement increased creatine levels in key brain regions, and participants reported feeling less fatigued, had faster reaction times on thinking tests, and showed stronger hand grip strength. The supplement was well tolerated with no side effects reported.

Cognitive Impairment

E3 PreliminaryMechanismPEM not requiredMechanistic

Effect of electroacupuncture on expression of protein phosphorylation in hippocampus tissues of rats with chronic fatigue syndrome.

Yang, Yan, Sun, Zhong-Ren, Li, Chao-Ran et al.·Zhen ci yan jiu = Acupuncture research·2024

Researchers used a rat model of chronic fatigue to test whether electroacupuncture (needle stimulation with electrical current) could improve fatigue symptoms and brain function. After 28 days of treatment, rats receiving electroacupuncture showed improvements in behavioural tests and changes in brain proteins compared to untreated fatigue-model rats, though this is a preliminary animal study and results in rats do not automatically translate to humans with ME/CFS.

Cognitive Impairment

E3 PreliminaryGuidelinePEM unclearGuideline

Improving quality in adult long covid services: Findings from the LOCOMOTION quality improvement collaborative.

Darbyshire, Julie, Greenhalgh, Trisha, Bakerly, Nawar D et al.·Clinical medicine (London, England)·2024

This study looked at how ten long COVID clinics across the UK could improve their care for patients by sharing what they were learning with each other. From 2021 to 2023, clinic staff and patients met regularly to discuss the best ways to help people with long COVID, focusing on problems like breathing difficulties, heart rate issues, tiredness, and brain fog. The team created practical guides to help doctors provide better, more consistent care.

Cognitive ImpairmentAutonomic Nervous System

E3 PreliminaryReviewPEM not requiredReview-Narrative

The interplay between Sars-Cov-2 infection related cardiovascular diseases and depression. Common mechanisms, shared symptoms.

Gonjilashvili, Ana, Tatishvili, Sophio·American heart journal plus : cardiology research and practice·2024

This review examines how COVID-19 can affect both the heart and mental health, and why these problems often occur together. The authors explain that inflammation, unhealthy lifestyle changes, and communication between organs may all play a role. They note that long COVID shares many symptoms with heart and brain problems—like fatigue, brain fog, dizziness, chest pain, and depression—which is why patients need care from multiple medical specialists.

Autonomic Nervous SystemCognitive Impairment

E3 PreliminaryGuidelinePEM unclearGuideline

Forming a consensus opinion to inform long COVID support mechanisms and interventions: a modified Delphi approach.

Owen, Rebecca, Ashton, Ruth E M, Ferraro, Francesco V et al.·EClinicalMedicine·2023

Researchers gathered opinions from doctors, physiotherapists, patients with Long COVID, and scientists across multiple countries to agree on the best ways to support and treat Long COVID. Using three rounds of surveys, they found strong agreement that Long COVID needs specialized, personalized care plans that address individual symptoms like fatigue, brain fog, and breathing problems, with emphasis on pacing and gradually returning to daily activities.

Cognitive Impairment

E3 PreliminaryMechanismPEM unclearCross-Sectional

Altered brain connectivity in Long Covid during cognitive exertion: a pilot study.

Barnden, Leighton, Thapaliya, Kiran, Eaton-Fitch, Natalie et al.·Frontiers in neuroscience·2023

Researchers used advanced brain imaging to compare how the brains of Long Covid patients and healthy people respond during a challenging thinking task. They found that Long Covid patients showed different patterns of communication between brain regions, particularly in areas that control alertness, heart rate, and sleep. These brain connection differences were linked to how disabled patients felt and their autonomic nervous system symptoms.

Cognitive Impairment

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

The Cognitive and Behavioural Responses to Symptoms Questionnaire (CBRQ): Development, reliability and validity across several long-term conditions.

Picariello, Federica, Chilcot, Joseph, Chalder, Trudie et al.·British journal of health psychology·2023

This study tested a questionnaire called the CBRQ that measures how people think about and respond to their symptoms in ways that might make them worse or keep them the same. The researchers checked whether this questionnaire works well across different long-term illnesses, including chronic fatigue syndrome (ME/CFS), and found that it reliably measures seven different thought and behaviour patterns. They also created and tested a shorter version of the questionnaire that works just as well.

Cognitive Impairment

E3 PreliminaryReviewPEM not requiredSystematic-Review

Understanding mental fatigue and its detection: a comparative analysis of assessments and tools.

Kunasegaran, Kaveena, Ismail, Ahamed Miflah Hussain, Ramasamy, Shamala et al.·PeerJ·2023

Mental fatigue is a common problem that makes it harder to concentrate, process information, and make decisions. Currently, doctors mainly ask patients to describe their fatigue using questionnaires, which can be unreliable because people's answers are subjective. This review compared different methods of detecting mental fatigue—including questionnaires, heart rate measurements, stress hormones, brain scans, and eye movement tests—to find the most objective and accurate tool.

Cognitive Impairment

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Behavioural problems associated with the chronic fatigue syndrome.

Fatigue, depression, and social adjustment in chronic fatigue syndrome.

Information processing efficiency in chronic fatigue syndrome and multiple sclerosis.

Quality of attention in chronic fatigue syndrome: subjective reports of everyday attention and cognitive difficulty, and performance on tasks of focused attention.

A brief mental fatigue questionnaire.

Attention and short-term memory in chronic fatigue syndrome patients: an event-related potential analysis.

Illness perception and symptom components in chronic fatigue syndrome.

Reduced Adenosine Triphosphate-to-Phosphocreatine Ratios in Neuropsychiatric Post-COVID Condition: Evidence From 31P Magnetic Resonance Spectroscopy.

Autonomic phenotyping, brain blood flow control, and cognitive-motor-integration in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome: A pilot study.

Dissecting the genetic complexity of myalgic encephalomyelitis/chronic fatigue syndrome via deep learning-powered genome analysis.

[Modern approaches to diagnosis and treatment of postinfectious asthenic syndrome in children].

Improvement in Upper Limb and Systemic Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Symptoms After Surgical Treatment of Neurogenic Thoracic Outlet Syndrome.

Six-Week Supplementation with Creatine in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Magnetic Resonance Spectroscopy Feasibility Study at 3 Tesla.

Effect of electroacupuncture on expression of protein phosphorylation in hippocampus tissues of rats with chronic fatigue syndrome.

Improving quality in adult long covid services: Findings from the LOCOMOTION quality improvement collaborative.

The interplay between Sars-Cov-2 infection related cardiovascular diseases and depression. Common mechanisms, shared symptoms.

Forming a consensus opinion to inform long COVID support mechanisms and interventions: a modified Delphi approach.

Altered brain connectivity in Long Covid during cognitive exertion: a pilot study.

The Cognitive and Behavioural Responses to Symptoms Questionnaire (CBRQ): Development, reliability and validity across several long-term conditions.

Understanding mental fatigue and its detection: a comparative analysis of assessments and tools.

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