Evidence browser

E2 ModerateBehavioralPEM not requiredCross-Sectional

A new case definition of Neuro-Inflammatory and Oxidative Fatigue (NIOF), a neuroprogressive disorder, formerly known as chronic fatigue syndrome or Myalgic Encephalomyelitis: results of multivariate pattern recognition methods and external validation by neuro-immune biomarkers.

Maes, Michael·Neuro endocrinology letters·2015

This study looked at whether ME/CFS could be better understood by examining specific blood markers related to inflammation, oxidative stress, and immune activation. Researchers found two distinct groups of people with chronic fatigue—one group had significantly higher levels of problematic immune markers and inflammatory signs. The study proposes a new way to identify ME/CFS based on fatigue plus at least four of these symptoms: muscle tension, memory problems, sleep issues, digestive problems, headaches, or flu-like feelings.

BiomarkersImmune System

The Self beyond Somatic Symptoms: A Narrative Approach to Self-Experience in Adolescent Chronic Fatigue Syndrome.

van Geelen, Stefan M, Fuchs, Coralie E, van Geel, Rolf et al.·Psychopathology·2015

This study looked at how adolescents with ME/CFS experience themselves and their identity, beyond just listing their symptoms. Researchers compared 42 teenagers with ME/CFS to teenagers with arthritis and healthy peers, and found that those with ME/CFS reported feeling more powerless, isolated, and unable to achieve their goals, while also having lower self-esteem and mental health scores. The findings suggest that ME/CFS deeply affects not just the body, but how young people see and value themselves.

E2 ModerateBehavioralPEM unclearCross-Sectional

Sleep characteristics, exercise capacity and physical activity in patients with chronic fatigue syndrome.

Aerenhouts, Dirk, Ickmans, Kelly, Clarys, Peter et al.·Disability and rehabilitation·2015

This study looked at how sleep problems and low activity levels are connected in people with ME/CFS. Researchers measured fitness capacity, sleep patterns, and daily activity in 42 women with ME/CFS and compared them to 24 healthy inactive women. People with ME/CFS slept more, spent more time in bed, had difficulty falling asleep and staying asleep, and were less physically active than the control group.

Sleep

Pain in people with chronic fatigue syndrome/myalgic encephalomyelitis: the role of traumatic stress and coping strategies.

Krzeczkowska, Anna, Karatzias, Thanos, Dickson, Adele·Psychology, health & medicine·2015

This study looked at pain in people with ME/CFS and how they cope with it. Researchers compared 27 people with ME/CFS to 27 healthy people and found that those with ME/CFS experienced more pain and had different coping strategies. People with ME/CFS who had severe pain were less likely to use helpful coping methods like accepting their situation or thinking positively about it.

Pain and Sensitization

E2 ModerateCohortPEM unclearObservational

Distinct plasma immune signatures in ME/CFS are present early in the course of illness.

Hornig, Mady, Montoya, José G, Klimas, Nancy G et al.·Science advances·2015

This study found that people with ME/CFS have distinctive patterns of immune system markers in their blood, but only early in the disease. Researchers compared blood samples from 52 people with early-stage ME/CFS to 348 healthy people and 246 people with long-standing ME/CFS. The early-stage group showed heightened immune activity that was not present in people who had been sick longer, suggesting the disease's immune profile changes over time.

BiomarkersImmune System

Chronic multisymptom illness among female Veterans deployed to Iraq and Afghanistan.

Mohanty, April F, Muthukutty, Anusha, Carter, Marjorie E et al.·Medical care·2015

This study looked at how common chronic multisymptom illnesses—including chronic fatigue syndrome, fibromyalgia, and irritable bowel syndrome—are among female veterans who deployed to Iraq and Afghanistan. Researchers found that these conditions were more than twice as common in this group compared to other female veterans. The study suggests that deployment experiences may play a role in developing these illnesses.

Chronic fatigue syndrome versus sudden onset myalgic encephalomyelitis.

Jason, Leonard A, Evans, Meredyth, Brown, Abigail et al.·Journal of prevention & intervention in the community·2015

This study looked at whether using a specific definition of ME (sudden onset myalgic encephalomyelitis) identifies a sicker group of patients compared to the broader CFS (chronic fatigue syndrome) definition. Researchers found that people who met the ME criteria had more severe symptoms, greater disability, and worse post-exertional malaise (feeling much worse after physical activity) than those meeting only the CFS criteria. The findings suggest that the ME definition may identify patients with more serious illness.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

An investigation of symptoms predating CFS onset.

Evans, Meredyth, Barry, Morgan, Im, Young et al.·Journal of prevention & intervention in the community·2015

This study looked at whether ME/CFS patients had symptoms before their fatigue started. Current diagnostic rules only count symptoms that happen at the same time as fatigue or afterward. The researchers found that many patients did experience lasting symptoms—like allergies and asthma—before their main fatigue began. Understanding these earlier symptoms might help doctors better understand how ME/CFS develops.

Measuring substantial reductions in activity.

Schafer, Charles, Evans, Meredyth, Jason, Leonard A et al.·Journal of prevention & intervention in the community·2015

ME/CFS diagnosis requires showing a significant drop in daily activities, but doctors have struggled to measure this fairly. This study looked at different ways to measure activity levels—including work, quality of life surveys, and activity trackers—to find which method works best. The researchers found that tracking current work activities was the most useful way to show the substantial reduction in functioning that ME/CFS patients experience.

Attention network test: assessment of cognitive function in chronic fatigue syndrome.

Togo, Fumiharu, Lange, Gudrun, Natelson, Benjamin H et al.·Journal of neuropsychology·2015

This study tested whether a computer-based attention test called the Attention Network Task (ANT) could measure thinking and processing speed problems in ME/CFS patients. Researchers compared 41 ME/CFS patients (some with depression, some without) to 29 healthy controls and found that ME/CFS patients took longer to respond to tasks, especially when the tasks were complex, even though they made the same number of mistakes as controls. This suggests that slowed thinking speed, rather than errors, may be the main cognitive problem in ME/CFS.

Endogenous event-related potentials in patients with primary Sjögren's syndrome without central nervous system involvement.

Dziadkowiak, E, Sebastian, A, Wiland, P et al.·Scandinavian journal of rheumatology·2015

This study looked at brain electrical activity in patients with Sjögren's syndrome (an autoimmune disease affecting moisture-producing glands) to see if they had subtle thinking or processing problems. Researchers found that patients showed slightly delayed brain responses to cognitive tasks, and these delays were linked to how long they'd had the disease and how inflamed their salivary glands were. Patients with both Sjögren's syndrome and chronic fatigue syndrome showed different patterns than those with Sjögren's syndrome alone.

Study findings challenge the content validity of the Canadian Consensus Criteria for adolescent chronic fatigue syndrome.

Asprusten, Tarjei Tørre, Fagermoen, Even, Sulheim, Dag et al.·Acta paediatrica (Oslo, Norway : 1992)·2015

Researchers tested whether the Canadian Consensus Criteria—a set of guidelines used to diagnose ME/CFS in teenagers—actually identify meaningful differences between patients. They compared 120 adolescents with ME/CFS, grouping them by whether they met these criteria or not. The study found that the two groups were nearly identical in most disease markers and how they recovered over time, suggesting the criteria may not be capturing important real-world differences between patients.

E2 ModerateCohortPEM not requiredCase-Control

Prolonged fatigue in Ukraine and the United States: Prevalence and risk factors.

Friedberg, Fred, Tintle, Nathan, Clark, Jake et al.·Fatigue : biomedicine, health & behavior·2015

This study compared how common prolonged, disabling fatigue is in Ukraine versus the United States by surveying thousands of people in both countries. Researchers found that prolonged fatigue was more common in Ukraine (5.2%) than in the U.S. (3.7%), and identified different risk factors in each country—such as socioeconomic status, mood disorders, and various health conditions. Importantly, about one-fifth of people with prolonged fatigue had no other diagnosed medical or mental health condition.

Increased prevalence of two mitochondrial DNA polymorphisms in functional disease: Are we describing different parts of an energy-depleted elephant?

Boles, Richard G, Zaki, Essam A, Kerr, Jonathan R et al.·Mitochondrion·2015

This study found that two specific variations in mitochondrial DNA (the energy-producing structures in our cells) appear more frequently in people with ME/CFS and several other conditions that cause fatigue, pain, or dysfunction. The researchers looked at people with a particular genetic background and found that having one or both of these DNA variations was linked to increased risk of developing these conditions. This suggests these genetic variations may be a shared risk factor across multiple illnesses.

Energy Metabolism

E2 ModerateBehavioralPEM not requiredCross-Sectional

Perceived Fatigue Interference and Depressed Mood: Comparison of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients with Fatigued Breast Cancer Survivors.

Hall, Daniel L, Antoni, Michael H, Lattie, Emily G et al.·Fatigue : biomedicine, health & behavior·2015

This study compared how fatigue affects daily life in people with ME/CFS versus breast cancer survivors who experience fatigue. The researchers found that ME/CFS patients reported more severe fatigue and more depression than the cancer survivors. Importantly, in ME/CFS patients, higher depression was closely tied to greater fatigue-related problems in daily activities, suggesting that mood and fatigue interference may be connected in ways worth exploring for treatment.

E2 ModerateBehavioralPEM not requiredObservational

The pre-interventional psychiatric history - an underestimated confounder in benign intracranial lesions studies.

Wenz, H, Wenz, R, Groden, C et al.·Clinical neurology and neurosurgery·2015

This study looked at 103 patients who had surgery for benign brain tumors or aneurysms and were physically recovered afterward. Researchers found that patients with a history of psychiatric conditions before surgery reported worse quality of life, more sleep problems, more fatigue symptoms, and more PTSD symptoms after surgery compared to those without prior psychiatric history—even though both groups had similar physical recovery.

Sleep

Serum Immune Proteins in Moderate and Severe Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients.

Hardcastle, Sharni Lee, Brenu, Ekua Weba, Johnston, Samantha et al.·International journal of medical sciences·2015

This study looked at immune system proteins in the blood of people with ME/CFS, comparing those with moderate and severe illness to healthy people. Researchers found that different immune markers were present at different levels depending on how severe someone's illness was. This suggests that ME/CFS may actually involve different immune patterns in different people, which could help researchers better understand why treatments don't work the same way for everyone.

Immune System

E2 ModerateCohortPEM unclearCross-Sectional

Unintended Consequences of not Specifying Exclusionary Illnesses for Systemic Exertion Intolerance Disease.

Jason, Leonard A, Sunnquist, Madison, Kot, Bobby et al.·Diagnostics (Basel, Switzerland)·2015

Researchers studied a new proposed name and definition for ME/CFS called SEID (Systemic Exertion Intolerance Disease). They found that the new definition was much looser than the old one and incorrectly labeled people with depression and other illnesses as having SEID when they didn't actually have ME/CFS. This means the new definition could overestimate how many people have ME/CFS.

Diagnostics

Cognitive dysfunction in adolescents with chronic fatigue: a cross-sectional study.

Sulheim, Dag, Fagermoen, Even, Sivertsen, Øyvind Stople et al.·Archives of disease in childhood·2015

This study compared thinking and memory skills in teenagers with chronic fatigue to healthy teenagers. Teenagers with chronic fatigue performed worse on tests of processing speed (how fast they could think), working memory (holding information in mind), and learning new information. These differences were not explained by depression, anxiety, or sleep problems alone.