Evidence browser

E2 ModerateDiagnosticPEM requiredCross-Sectional

Comorbidity in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Nationwide Population-Based Cohort Study.

Castro-Marrero, Jesús, Faro, Mónica, Aliste, Luisa et al.·Psychosomatics·2017

This study looked at 1,757 people with ME/CFS in Spain to understand what other health conditions they commonly experience alongside their ME/CFS. Researchers found that more than 80% of patients had at least one additional condition, such as fibromyalgia, thyroid problems, vitamin D deficiency, or ligament issues. The study identified five different groups of ME/CFS patients based on their comorbidities, with some groups experiencing significantly worse fatigue and quality of life than others.

A Comparison of Case Definitions for Myalgic Encephalomyelitis and Chronic Fatigue Syndrome.

Sunnquist, Madison, Jason, Leonard A, Nehrke, Pamela et al.·Journal of chronic diseases and management·2017

This study compared two different sets of diagnostic criteria used to identify ME/CFS patients. Researchers found that 76% of people diagnosed with chronic fatigue syndrome met the newer Institute of Medicine criteria, but only 44% met the revised London criteria. The London criteria identified patients who were more severely physically impaired, suggesting that different diagnostic tools can identify different groups of patients.

Heterogeneity in chronic fatigue syndrome - empirically defined subgroups from the PACE trial.

Williams, T E, Chalder, T, Sharpe, M et al.·Psychological medicine·2017

This study found that ME/CFS is not one single condition but rather five distinct subtypes that affect people differently. Researchers analyzed data from 541 patients and identified groups characterized by: low overall symptoms, mood disorders, overlapping conditions like fibromyalgia, combined multiple symptoms, or avoidance behaviors with fear of activity. Understanding these differences could help doctors tailor treatments to what works best for each person's specific type.

Differentiating Multiple Sclerosis from Myalgic Encephalomyelitis and Chronic Fatigue Syndrome.

Jason, L A, Ohanian, D, Brown, A et al.·Insights in biomedicine·2017

This study compared how people with MS, ME, and chronic fatigue syndrome experience their illnesses. Researchers surveyed 120 people with MS and 269 people with ME/CFS about their symptoms using a standardized questionnaire. They found that people with ME/CFS reported more severe symptoms and greater functional limitations than people with MS, suggesting these conditions have different disability profiles.

E2 ModerateDiagnosticPEM not requiredMethods-Paper

The assessment of fatigue: Psychometric qualities and norms for the Checklist individual strength.

Worm-Smeitink, M, Gielissen, M, Bloot, L et al.·Journal of psychosomatic research·2017

This study tested a questionnaire called the Checklist Individual Strength (CIS) that measures different types of fatigue, including how tired people feel, difficulty concentrating, lack of motivation, and reduced activity levels. Researchers gave this questionnaire to nearly 2,300 healthy people and over 5,000 patients with chronic fatigue to see if it accurately identifies severe fatigue. They found the CIS works well for measuring fatigue and recommended adjusting the score that indicates 'severe fatigue' from 35 to 40 points for ME/CFS research.

E2 ModerateCohortPEM not requiredObservational

Current Safety Concerns with Human Papillomavirus Vaccine: A Cluster Analysis of Reports in VigiBase®.

Chandler, Rebecca E, Juhlin, Kristina, Fransson, Jonas et al.·Drug safety·2017

Researchers analyzed thousands of reports from a global database of side effects following HPV vaccination. They found that certain combinations of symptoms—headaches, dizziness, fatigue, and fainting—were reported more often after HPV vaccination than with other vaccines, particularly in young women. These symptom clusters resemble conditions like POTS, CRPS, and chronic fatigue syndrome, though most reports did not include an official diagnosis.

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM not requiredCase-Control

RNA-Seq Analysis of Gene Expression, Viral Pathogen, and B-Cell/T-Cell Receptor Signatures in Complex Chronic Disease.

Bouquet, Jerome, Gardy, Jennifer L, Brown, Scott et al.·Clinical infectious diseases : an official publication of the Infectious Diseases Society of America·2017

Researchers used genetic testing to compare blood samples from people with ME/CFS and a similar condition called alternative Lyme disease to healthy controls and people with lupus. They looked for differences in gene activity, immune cell patterns, and viral infections. Surprisingly, they found no major differences in gene activity between ME/CFS patients and healthy people, though they did find differences in lupus patients as expected.

Immune System

E2 ModerateCohortPEM not requiredObservational

Epigenetic modifications and glucocorticoid sensitivity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

de Vega, Wilfred C, Herrera, Santiago, Vernon, Suzanne D et al.·BMC medical genomics·2017

This study looked at chemical tags attached to DNA in immune cells from ME/CFS patients and compared them to healthy people. Researchers found that ME/CFS patients had different patterns of these chemical tags, especially in genes related to how cells produce energy. Some of these differences were linked to patients' reported quality of life, suggesting that changes in how genes are regulated may contribute to ME/CFS symptoms.

Immune System

Specialist treatment of chronic fatigue syndrome/ME: a cohort study among adult patients in England.

Collin, Simon M, Crawley, Esther·BMC health services research·2017

This study looked at how 952 ME/CFS patients fared after receiving treatment at 11 specialist NHS clinics in England. One year after starting treatment, about 27% felt much better, 37% felt a little better, but 20% felt the same or worse. Even 2-5 years later, 85% of patients still had ME/CFS symptoms, showing that this is a long-lasting condition that often continues despite specialist care.

Pain and SensitizationSleep

E2 ModerateBehavioralPEM not requiredCross-Sectional

Brain 18F-FDG PET Metabolic Abnormalities in Patients with Long-Lasting Macrophagic Myofascitis.

Van Der Gucht, Axel, Aoun Sebaiti, Mehdi, Guedj, Eric et al.·Journal of nuclear medicine : official publication, Society of Nuclear Medicine·2017

This study used a special type of brain scan (PET imaging) to look for energy metabolism problems in the brains of people with macrophagic myofascitis, a condition involving immune cell buildup in muscles. Researchers found that MMF patients had lower energy use in multiple brain regions compared to healthy people, and this pattern was especially pronounced in patients who also had thinking and memory problems.

Cognitive Impairment

Fatigue in an adult attention deficit hyperactivity disorder population: A trans-diagnostic approach.

Rogers, Denise C, Dittner, Antonia J, Rimes, Katharine A et al.·The British journal of clinical psychology·2017

This study looked at fatigue in adults with ADHD and compared it to fatigue in people with ME/CFS and healthy people. Researchers found that adults with ADHD experience significantly more fatigue than healthy controls, with about 62% meeting criteria for clinically significant fatigue. Importantly, they discovered that people with ME/CFS and people with ADHD share many similar challenges, including low mood, anxiety, and reduced confidence in their abilities.

Cognitive Impairment

Gross and fine motor function in fibromyalgia and chronic fatigue syndrome.

Rasouli, Omid, Fors, Egil A, Borchgrevink, Petter Chr et al.·Journal of pain research·2017

This study compared how quickly people with ME/CFS and fibromyalgia could start moving when they heard a sound, and how well they could do precise hand movements compared to healthy people. Both ME/CFS and fibromyalgia groups were slower to start walking in response to the sound, though their fine hand movements were similar to healthy controls. The results suggest that ME/CFS and fibromyalgia may affect the speed of starting movement, but not the precision of hand tasks.

E2 ModerateCohortPEM unclearCase-Control

Access to Medical Care for Individuals with Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: A Call for Centers of Excellence.

Sunnquist, Madison, Nicholson, Laura, Jason, Leonard A et al.·Modern clinical medicine research·2017

This study asked nearly 900 people with ME/CFS about their experiences finding and receiving medical care. The researchers found that less than half had ever seen a doctor who specializes in ME/CFS, even though almost everyone wanted to. The biggest obstacles were distance to specialists and cost, and patients were much happier with care from ME/CFS specialists than from doctors who didn't specialize in these conditions.

Health care resource use by patients before and after a diagnosis of chronic fatigue syndrome (CFS/ME): a clinical practice research datalink study.

Collin, Simon M, Bakken, Inger J, Nazareth, Irwin et al.·BMC family practice·2017

This study looked at doctor visits, tests, prescriptions, and referrals for people diagnosed with ME/CFS compared to similar people without the condition. Researchers found that people who were later diagnosed with ME/CFS visited their doctors much more frequently—both years before they received their diagnosis and for at least 10 years afterward. This suggests that people with ME/CFS have ongoing, significant health needs that require more medical care than the general population.

E2 ModerateBehavioralPEM unclearCross-Sectional

Anxiety and depression in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME): Examining the incidence of health anxiety in CFS/ME.

Daniels, Jo, Brigden, Amberly, Kacorova, Adela·Psychology and psychotherapy·2017

This study looked at how many people with ME/CFS also experience health anxiety—worry about physical symptoms and their meaning. Researchers surveyed 45 ME/CFS patients and found that most had elevated worry about their health, and many had clinically significant health anxiety. The findings suggest that health anxiety is common in ME/CFS and may be worth screening for and treating.

E2 ModerateCohortPEM unclearObservational

Down-regulation of renin-aldosterone and antidiuretic hormone systems in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Miwa, Kunihisa·Journal of cardiology·2017

This study found that ME/CFS patients have smaller hearts and lower levels of certain hormones that control blood volume and fluid balance compared to healthy people. When researchers gave half the ME/CFS patients a synthetic hormone called desmopressin for five days, about half of them felt better, with less dizziness when standing and improved ability to do daily activities.

Autonomic Nervous System

E2 ModerateCohortPEM requiredCross-Sectional

Neuroendocrine disorder in chronic fatigue syndrome.

Tomic, Slavica, Brkic, Snezana, Lendak, Dajana et al.·Turkish journal of medical sciences·2017

This study looked at hormone levels in 40 women with ME/CFS compared to 40 healthy women to see if hormonal imbalances might explain ME/CFS symptoms. While standard hormone tests showed mostly normal results, researchers found that cortisol (a stress hormone) didn't follow its natural daily rhythm in ME/CFS patients the way it does in healthy people, and thyroid hormone T3 was lower in the ME/CFS group. The findings suggest that ME/CFS may involve subtle disruptions in how the body regulates these hormones over time.

Endocrine Disruption

Clinical Criteria Versus a Possible Research Case Definition in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis.

Jason, Leonard A, McManimen, Stephanie, Sunnquist, Madison et al.·Fatigue : biomedicine, health & behavior·2017

This study compared different ways of defining ME/CFS to see which one best identifies the sickest patients. Researchers looked at over 1,000 patients from multiple countries and found that using stricter criteria—specifically focusing on people who are homebound and meet core ME/CFS symptoms—identified a group with more severe symptoms and greater disability than the broader clinical definition. The researchers suggest that having a clear, standardized research definition would help scientists compare patients more fairly across different studies.

Immune network analysis of cerebrospinal fluid in myalgic encephalomyelitis/chronic fatigue syndrome with atypical and classical presentations.

Hornig, M, Gottschalk, C G, Eddy, M L et al.·Translational psychiatry·2017

This study examined fluid from around the brain and spinal cord in people with ME/CFS to look for immune system differences. Researchers found that people whose ME/CFS started differently (without a clear infection trigger) had different patterns of immune molecules compared to those with typical ME/CFS that started after a viral-like illness. The atypical group had lower levels of certain inflammatory markers and less coordinated immune activity in their central nervous system.

Immune System