Evidence browser

E0 ConsensusReviewPEM unclearSystematic-Review

Chronic fatigue syndrome.

Reid, S, Chalder, T, Cleare, A et al.·BMJ (Clinical research ed.)·2000

This was a systematic review that brought together existing research about chronic fatigue syndrome (ME/CFS) to understand what was known at the time. The researchers looked at multiple studies to summarize the current evidence about the condition. This type of overview helps doctors and patients understand the state of knowledge about ME/CFS.

Interventions

The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders.

Heim, C, Ehlert, U, Hellhammer, D H·Psychoneuroendocrinology·2000

This review examines why some people under chronic stress or after trauma have abnormally low levels of the stress hormone cortisol—a condition called hypocortisolism. The authors found that low cortisol appears in several conditions including ME/CFS, fibromyalgia, and rheumatoid arthritis, not just in PTSD. They propose that persistently low cortisol may make people more vulnerable to developing stress-related illnesses.

Endocrine Disruption

E0 ConsensusReviewPEM not requiredSystematic-Review

Cognitive behaviour therapy for adults with chronic fatigue syndrome.

Price, J R, Couper, J·The Cochrane database of systematic reviews·2000

This review examined whether cognitive behaviour therapy (CBT)—a type of talk therapy that helps people change unhelpful thinking patterns and gradually return to activities—helps adults with ME/CFS. Researchers looked at three high-quality studies and found that CBT did improve physical functioning compared to standard medical care or relaxation therapy. However, the evidence was limited to people who could attend clinic appointments; more research is needed in people with milder or more severe forms of the illness.

Interventions

Review of clinical and psychobiological dimensions of the chronic fatigue syndrome: differentiation from depression and contribution of sleep dysfunctions.

Fischler, B·Sleep medicine reviews·1999

This review examined how ME/CFS differs from depression and what role sleep problems play in the condition. The researchers found that ME/CFS is a distinct illness with its own biological features—not just depression wearing a different mask. While sleep problems are common in ME/CFS, they don't fully explain why patients feel so exhausted and unwell.

Sleep

Chronic fatigue syndrome: reviewing the research findings.

Johnson, S K, DeLuca, J, Natelson, B H·Annals of behavioral medicine : a publication of the Society of Behavioral Medicine·1999

This review article examines what scientists have learned about ME/CFS by looking at many different studies. Researchers found that ME/CFS is complex—it likely involves multiple causes including viral infections, immune system problems, nervous system dysfunction, and possibly psychological factors. The article emphasizes that ME/CFS affects different people in different ways, suggesting that patients may benefit from being grouped by their symptoms and illness history rather than treated as one uniform condition.

Immune System

Functional somatic syndromes: one or many?

Wessely, S, Nimnuan, C, Sharpe, M·Lancet (London, England)·1999

This study looked at several long-term illnesses that cause many physical symptoms but don't show obvious damage on standard medical tests, including ME/CFS and irritable bowel syndrome. The researchers found that these conditions have much more in common with each other than previously thought—they affect similar types of patients, cause overlapping symptoms, and respond to treatment in similar ways. Rather than treating each condition as completely separate, the authors suggest doctors and researchers should think of them as related conditions on a spectrum.

Review of juvenile primary fibromyalgia and chronic fatigue syndrome.

Breau, L M, McGrath, P J, Ju, L H·Journal of developmental and behavioral pediatrics : JDBP·1999

This review examined research on fibromyalgia and chronic fatigue syndrome (ME/CFS) in children. The authors found that these conditions in young people may work differently than they do in adults, and that they might be more closely related to each other than previously thought. The review suggests that these illnesses are likely caused by biological and genetic factors rather than psychological problems.

E0 ConsensusReviewPEM not requiredEditorial

Chronic fatigue syndrome: an immunological perspective.

Vollmer-Conna, U, Lloyd, A, Hickie, I et al.·The Australian and New Zealand journal of psychiatry·1998

This review examines whether immune system problems might cause ME/CFS symptoms, particularly in the brain. The researchers found that while immune chemicals called cytokines are likely involved in ME/CFS, the results from studies measuring these chemicals in the blood have been mixed and unclear. They suggest that abnormal cytokine activity happening directly inside the brain—rather than in the bloodstream—may be more important for explaining the neurological symptoms patients experience.

Immune System

Chronic fatigue and chronic fatigue syndrome: shifting boundaries and attributions.

Lloyd, A R·The American journal of medicine·1998

This review examines how fatigue is defined and diagnosed, and how different definitions lead to very different estimates of how many people have chronic fatigue syndrome. The authors look at how doctors and researchers measure fatigue using patient reports, and explore whether fatigue that follows infections is a real medical condition. The study highlights that without clear, consistent definitions, it's difficult to understand the true scope of the problem.

Cognitive behavior therapy for chronic fatigue syndrome: efficacy and implications.

Sharpe, M·The American journal of medicine·1998

This review examines cognitive behavior therapy (CBT), a talk-based treatment that helps people change thought patterns and behaviors that may be making their fatigue worse. Research from two rigorous clinical trials shows that CBT can significantly help people with ME/CFS feel better and become more active. While most people improve, complete recovery is rare.

Interventions

Chronic fatigue syndrome in children and adolescents: a review.

Jordan, K M, Landis, D A, Downey, M C et al.·The Journal of adolescent health : official publication of the Society for Adolescent Medicine·1998

This review examined what was known about ME/CFS (chronic fatigue syndrome) specifically in children and teenagers. The authors looked at existing research to understand how the illness affects young people, how doctors recognize it, and what happens to patients over time. This study helps explain what ME/CFS looks like in younger patients, which is often different from how it appears in adults.

Autonomic Nervous SystemImmune System

Chronic pain and fatigue syndromes: overlapping clinical and neuroendocrine features and potential pathogenic mechanisms.

Clauw, D J, Chrousos, G P·Neuroimmunomodulation·1997

This review examines fibromyalgia and chronic fatigue syndrome, two conditions with overlapping symptoms of pain and exhaustion that have been described throughout medical history under different names. The authors propose that both conditions stem from problems in the central nervous system—the brain and spinal cord—particularly in areas that control hormone levels, pain sensing, and automatic body functions. They suggest that immune system changes seen in these conditions are side effects rather than root causes.

E0 ConsensusReviewPEM not requiredSystematic-Review

The prognosis of chronic fatigue and chronic fatigue syndrome: a systematic review.

Joyce, J, Hotopf, M, Wessely, S·QJM : monthly journal of the Association of Physicians·1997

This review looked at many studies of ME/CFS to see how many people get better over time. The results showed that children recover more often (54-94%) than adults, and adults with a strict ME/CFS diagnosis rarely return to their previous level of functioning. People who are older, have other illnesses, have depression or anxiety, or believe their illness is physical in origin tend to have worse outcomes.

Epidemiologic advances in chronic fatigue syndrome.

Levine, P H·Journal of psychiatric research·1997

This review summarized what researchers knew about ME/CFS in 1997, including how common it is, who gets it, and what affects recovery. The study found that about 200 out of every 100,000 people have ME/CFS, and that women are more likely to develop it than men. The review also noted that people with sudden-onset ME/CFS tend to recover better than those whose symptoms start gradually.

Neuropsychology of chronic fatigue syndrome: a critical review.

Tiersky, L A, Johnson, S K, Lange, G et al.·Journal of clinical and experimental neuropsychology·1997

This review examined research on thinking and memory problems in ME/CFS patients. The clearest finding was that people with ME/CFS struggle with processing information quickly and efficiently, similar to when your brain feels sluggish. However, overall intelligence and complex thinking skills remain normal. Emotional factors like anxiety or depression can make cognitive problems feel worse, though it's unclear if they directly affect actual thinking performance.

Cognitive Impairment

War syndromes and their evaluation: from the U.S. Civil War to the Persian Gulf War.

Hyams, K C, Wignall, F S, Roswell, R·Annals of internal medicine·1996

Researchers reviewed historical records of illnesses that appeared in soldiers after wars, dating back to the U.S. Civil War through the Persian Gulf War. They found that across different wars and time periods, veterans reported similar symptoms like exhaustion, breathing problems, headaches, and difficulty concentrating. However, the researchers concluded that these symptoms don't appear to be one single disease, and that lack of proper comparison groups and research methods made it hard to determine what actually caused these illnesses.

Cognitive Impairment

Neurocognitive functioning in chronic fatigue syndrome.

DiPino, R K, Kane, R L·Neuropsychology review·1996

This review examined research on thinking and memory problems reported by people with ME/CFS. While patients consistently describe difficulties concentrating and remembering things, scientific tests of these abilities have shown mixed and unclear results. The authors suggest that researchers need to improve how they design studies and what tests they use to better understand these cognitive challenges.

Cognitive Impairment

The management of treatment-resistant depression in disorders on the interface of psychiatry and medicine. Fibromyalgia, chronic fatigue syndrome, migraine, irritable bowel syndrome, atypical facial pain, and premenstrual dysphoric disorder.

Gruber, A J, Hudson, J I, Pope, H G·The Psychiatric clinics of North America·1996

This review examined whether antidepressant medications help treat several chronic conditions—including ME/CFS, fibromyalgia, migraines, and irritable bowel syndrome—that often occur alongside depression. The researchers found that many different types of antidepressants appeared to benefit these disorders, suggesting they might share a common underlying biological problem. However, the studies reviewed varied widely in quality and design, so stronger research is needed to confirm these findings.

Fibromyalgia and chronic fatigue syndrome: similarities and differences.

Buchwald, D·Rheumatic diseases clinics of North America·1996

This review compared ME/CFS and fibromyalgia (FM), two conditions that cause fatigue, muscle pain, and sleep problems. The researchers found that these two illnesses are very similar in their symptoms and how they affect people's lives, even though doctors use different criteria to diagnose them. Some patients have both conditions at the same time, which makes their suffering worse.

SleepDiagnostics