Evidence browser

Pain and SensitizationCognitive Impairment

Dysfunctional syndromes and fibromyalgia: a 2012 critical digest.

Sarzi-Puttini, Piercarlo, Atzeni, Fabiola, Di Franco, Manuela et al.·Clinical and experimental rheumatology·2012

This review looked at several long-lasting conditions that cause widespread pain, tiredness, sleep problems, and difficulty concentrating—conditions that don't always show up clearly on standard medical tests. The researchers examined fibromyalgia, ME/CFS, and irritable bowel syndrome to understand how they're connected and what causes symptoms to keep happening. They found that these conditions share similar patterns in how the nervous system processes pain and fatigue.

A review of the definitional criteria for chronic fatigue syndrome.

Christley, Yvonne, Duffy, Tim, Martin, Colin R·Journal of evaluation in clinical practice·2012

Doctors have been trying to agree on how to diagnose ME/CFS for over 30 years, but they still don't have a single agreed-upon definition. This review looked at five different official definitions that doctors use to diagnose the condition. The most commonly used definition, from the CDC in 1994, has never been proven to be better than the others and has been criticized for not being specific enough.

Diagnostics

In the mind or in the brain? Scientific evidence for central sensitisation in chronic fatigue syndrome.

Nijs, Jo, Meeus, Mira, Van Oosterwijck, Jessica et al.·European journal of clinical investigation·2012

This review examined whether ME/CFS involves a nervous system that becomes overly sensitive to pain and other sensations. Researchers found that people with ME/CFS do show heightened responses to various types of stimuli—including touch, pressure, heat, and electrical stimulation—across multiple body areas. Importantly, this nervous system sensitivity tends to get worse, not better, after exercise or stress, suggesting a fundamental difference in how the central nervous system responds in ME/CFS.

Post-Exertional Malaise

E0 ConsensusReviewPEM unclearSystematic-Review

Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Jason, Leonard A, Barker, Kristen, Brown, Abigail·Reviews in health care·2012

This review examines how ME/CFS affects children and teenagers, which can be quite different from how it affects adults. The authors looked at existing research on how common pediatric ME/CFS is, how doctors diagnose it, what treatments are available, and what happens to children over time. They identified important gaps in our understanding and call for better ways to recognize and help young people with this condition.

Diagnostics

A review and meta-synthesis of qualitative studies on myalgic encephalomyelitis/chronic fatigue syndrome.

Anderson, Valerie R, Jason, Leonard A, Hlavaty, Laura E et al.·Patient education and counseling·2012

This study looked at 34 research articles that asked ME/CFS patients and doctors about their experiences with the illness. Researchers found that patients struggle with how the disease changes their identity and ability to function, while doctors often lack knowledge about ME/CFS. A major problem identified was that difficulty getting a diagnosis creates stress, misunderstanding, and unfair treatment of patients with this illness.

The prevalence of fibromyalgia in other chronic pain conditions.

Yunus, Muhammad B·Pain research and treatment·2012

This review examined how often fibromyalgia (a condition causing widespread pain and fatigue) occurs alongside other chronic pain conditions, including ME/CFS. The researchers found that fibromyalgia frequently co-occurs with conditions like rheumatoid arthritis, lupus, and osteoarthritis, and that it can be missed or misdiagnosed in people who have these other diseases. Recognizing fibromyalgia separately is important because it may change how doctors treat patients and what medications they use.

Pain and Sensitization

E0 ConsensusReviewPEM not requiredSystematic-Review

Biomarkers for chronic fatigue.

Klimas, Nancy G, Broderick, Gordon, Fletcher, Mary Ann·Brain, behavior, and immunity·2012

This review examines blood tests and biological markers that might help diagnose ME/CFS, since current diagnosis relies only on symptoms. The researchers found that multiple body systems—including the immune system, stress hormones, and nervous system—appear to be disrupted in ME/CFS patients. However, no single test yet reliably identifies the condition, suggesting ME/CFS may involve complex changes across several systems rather than one simple cause.

Immune System

How to exercise people with chronic fatigue syndrome: evidence-based practice guidelines.

Van Cauwenbergh, Deborah, De Kooning, Margot, Ickmans, Kelly et al.·European journal of clinical investigation·2012

This review looked at research studies about exercise therapy for ME/CFS to figure out the best way to recommend exercise to patients. Based on 12 high-quality studies, the researchers found that aerobic exercise (like walking or cycling) works best when done about 10-11 times over 4-5 months, starting with 5-15 minute sessions at home and gradually building up to 30 minutes. They recommend increasing exercise based on time rather than how you're feeling that day.

Overlap between functional GI disorders and other functional syndromes: what are the underlying mechanisms?

Kim, S E, Chang, L·Neurogastroenterology and motility·2012

Many patients with ME/CFS experience overlapping conditions like irritable bowel syndrome, fibromyalgia, and jaw pain. This review looked at what ME/CFS and similar conditions might have in common. The researchers found that these disorders likely share several underlying problems: how the body processes pain, changes in brain activity, possible past infections, immune system problems, and genetic factors that make some people more vulnerable.

Immune System

E0 ConsensusReviewPEM unclearSystematic-Review

Meta-analysis and meta-regression of hypothalamic-pituitary-adrenal axis activity in functional somatic disorders.

Tak, Lineke M, Cleare, Anthony J, Ormel, Johan et al.·Biological psychology·2011

This research reviewed 85 studies examining whether people with ME/CFS, fibromyalgia, and irritable bowel syndrome have lower levels of the stress hormone cortisol. The researchers found that ME/CFS patients do have lower cortisol levels compared to healthy people, though the difference was modest. Being female also predicted lower cortisol, particularly in fibromyalgia patients.

Endocrine Disruption

Complementary and alternative medicine for patients with chronic fatigue syndrome: a systematic review.

Alraek, Terje, Lee, Myeong Soo, Choi, Tae-Young et al.·BMC complementary and alternative medicine·2011

This review looked at 26 high-quality studies testing whether complementary and alternative medicines (CAM) help ME/CFS symptoms. Researchers found that some treatments like massage, tuina, and qigong showed promise, while others like homeopathy and distant healing did not work better than placebo. Most supplements tested didn't help, except for NADH and magnesium, though the evidence overall was limited.

NeuroinflammationImmune System

An intriguing and hitherto unexplained co-occurrence: Depression and chronic fatigue syndrome are manifestations of shared inflammatory, oxidative and nitrosative (IO&NS) pathways.

Maes, Michael·Progress in neuro-psychopharmacology & biological psychiatry·2011

Depression and ME/CFS often occur together, and this study suggests they share common biological root causes involving inflammation and oxidative stress (damage to cells). While depression and ME/CFS look different clinically, they appear to involve similar underlying problems with the immune system, energy production, and antioxidant defenses. The authors argue these should be considered connected disorders rather than two separate conditions that happen to co-occur.

NeuroinflammationImmune System

Meta analysis of Chronic Fatigue Syndrome through integration of clinical, gene expression, SNP and proteomic data.

Pihur, Vasyl, Datta, Somnath, Datta, Susmita·Bioinformation·2011

Researchers combined multiple types of biological data from ME/CFS patients and healthy controls to identify genes that may contribute to ME/CFS and its severity. They found 11 genes of potential importance, with one gene called WASF3 standing out as possibly influencing fatigue through a specific cellular pathway in the brain.

E0 ConsensusReviewPEM not requiredSystematic-Review

Chronic fatigue syndrome.

Reid, Steven, Chalder, Trudie, Cleare, Anthony et al.·BMJ clinical evidence·2011

This review looked at treatments for ME/CFS by examining 46 high-quality studies published up to March 2010. The researchers assessed which treatments—including antidepressants, exercise therapy, cognitive behavioral therapy, and supplements—actually work and are safe. The review shows that ME/CFS affects less than 3% of people, with more women than men experiencing the condition.

E0 ConsensusReviewPEM not requiredSystematic-Review

Daily physical activity of patients with the chronic fatigue syndrome: a systematic review.

Evering, Richard M H, van Weering, Marit G H, Groothuis-Oudshoorn, Karin C G M et al.·Clinical rehabilitation·2011

This review looked at 17 studies comparing how physically active people with ME/CFS are compared to healthy people. The research found that people with ME/CFS are significantly less active than healthy controls—doing only about 68% of the physical activity of healthy people. The studies also found that day-to-day variation in activity levels was similar between the two groups.

E0 ConsensusReviewPEM unclearObservational

Anxiety in children and adolescents with chronic physical illnesses: a meta-analysis.

Pinquart, Martin, Shen, Yuhui·Acta paediatrica (Oslo, Norway : 1992)·2011

This large review combined results from 332 studies to compare anxiety levels in children with chronic illnesses versus healthy children. Children with chronic illnesses, including ME/CFS, showed higher levels of anxiety than their healthy peers. ME/CFS was among the conditions most strongly linked to anxiety in children.

Treating chronic fatigue syndrome - a study into the scientific evidence for pharmacological treatments.

Kreijkamp-Kaspers, Sanne, Brenu, Ekua Weba, Marshall, Sonya et al.·Australian family physician·2011

This study looked at what medicines and supplements 94 people with ME/CFS were taking and checked what scientific evidence supported their use. The patients were using hundreds of different treatments, with antidepressants, pain relievers, sleep aids, and B vitamins being the most common. However, when researchers searched for rigorous studies proving these treatments work for ME/CFS, they found very limited evidence—only 20 good-quality trials existed for the medicines patients were using.

Interventions

E0 ConsensusReviewPEM not requiredSystematic-Review

Depressive symptoms in children and adolescents with chronic physical illness: an updated meta-analysis.

Pinquart, Martin, Shen, Yuhui·Journal of pediatric psychology·2011

This large review looked at 340 studies to see whether children and teens with chronic illnesses experience more depression than healthy children. The researchers found that on average, children with chronic illnesses do report higher levels of depression, with ME/CFS showing the strongest link. The study recommends that doctors working with chronically ill children routinely check for depression and refer them to mental health support when needed.

Homeopathic treatments in psychiatry: a systematic review of randomized placebo-controlled studies.

Davidson, Jonathan R T, Crawford, Cindy, Ives, John A et al.·The Journal of clinical psychiatry·2011

This review looked at 25 studies testing whether homeopathic treatments help with psychiatric conditions like anxiety, depression, and sleep problems. The researchers found some evidence that homeopathy might help with chronic fatigue syndrome and fibromyalgia, but it did not help with anxiety or stress. Overall, the quality of the studies was mixed, and more research is needed to draw firm conclusions.

Sleep