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Chronic fatigue syndrome (CFS) is the most common name given to a poorly understood, variably debilitating disorder or disorders of uncertain causation. It is also commonly known as myalgic encephalomyelitis or ME.
Symptoms of CFS include widespread muscle and joint pain, cognitive difficulties, chronic, often severe mental and physical exhaustion and other characteristic symptoms in a previously healthy and active person. Fatigue is a common symptom in many illnesses, but CFS is a multi-systemic disease and is relatively rare by comparison. Diagnosis requires a number of features the most common being severe mental and physical exhaustion which is "unrelieved by rest," is worsened by exertion and is present for at least six months. All diagnostic criteria require that the symptoms must not be caused by other medical conditions. CFS patients may report additional symptoms  including muscle weakness, cognitive dysfunction, hypersensitivity, orthostatic intolerance, digestive disturbances, depression, poor immune response, cardiac and respiratory problems. It is unclear if these symptoms represent co-morbid conditions or are produced by an underlying etiology of CFS. Full resolution occurs in only 5-10% of cases.
CFS is thought to have an incidence of 4 adults per 1,000 in the United States. For unknown reasons CFS occurs most often in people in their 40s and 50s, and more often in women than men. The illness is estimated to be less prevalent among children and adolescents  but studies are contradictory as to the degree.  There is no medical test which is widely accepted to be diagnostic of CFS. It remains a diagnosis of exclusion based largely on patient history and symptomatic criteria although a number of tests can aid diagnosis.
Whereas there is agreement on the genuine threat to health, happiness, and productivity posed by CFS various physicians groups, researchers and patient advocates promote different nomenclature, diagnostic criteria, etiologic hypotheses and treatments, resulting in controversy about many aspects of the disorder. The name CFS itself is controversial as advocacy groups as well as some experts feel it trivializes the illness and have supported efforts to change it. Many alternative names for chronic fatigue syndrome exist.
Signs and symptoms
The majority of CFS cases start suddenly, usually accompanied by a "flu-like illness" which is more likely to occur in winter, while a significant proportion of cases begin within several months of severe adverse stress. An Australian prospective study found that after infection by viral and non-viral pathogens, a sub-set of individuals met the criteria for CFS, with the researchers concluding that "post-infective fatigue syndrome is a valid illness model for investigating one pathophysiological pathway to CFS". However, accurate prevalence and exact roles of infection and stress in the development of CFS are currently unknown.
The most commonly used diagnostic criteria and definition of CFS for research and clinical purposes was published by the United States Centers for Disease Control and Prevention (CDC). The CDC definition of CFS requires two criteria be fulfilled:
A new onset (not lifelong) of unexplained, persistent fatigue unrelated to exertion and not substantially relieved by rest, that causes a significant reduction in previous activity levels.
Four or more of the following symptoms that last six months or longer:
Impaired memory or concentration
Post-exertional malaise, where physical or mental exertions bring on "extreme, prolonged exhaustion and sickness"
Muscle pain (myalgia)
Pain in multiple joints (arthralgia)
Headaches of a new kind or greater severity
Sore throat, frequent or recurring
Tender lymph nodes (cervical or axillary)
When symptoms are attributable to other conditions, the diagnosis of CFS is excluded. The CDC specifically refers to several illnesses with symptoms resembling those of CFS: "mononucleosis, Lyme disease, lupus, multiple sclerosis, fibromyalgia, primary sleep disorders, severe obesity and major depressive disorders. Medications can also cause side effects that mimic the symptoms of CFS."
Patients report critical reductions in levels of physical activity with impairment comparable to other fatiguing medical conditions including multiple sclerosis, late-stage AIDS, lupus, rheumatoid arthritis, heart disease, end-stage renal disease, chronic obstructive pulmonary disease (COPD), and the effects of chemotherapy. The severity of symptoms and disability is the same in both genders with strongly disabling chronic pain, but despite a common diagnosis the functional capacity of individuals with CFS varies greatly. While some lead relatively normal lives, others are totally bed-ridden and unable to care for themselves. Employment rates vary with over half unable to work and nearly two-thirds limited in their work because of their illness. More than half were on disability benefits or temporary sick leave, and less than a fifth worked full-time.
Pathophysiology of chronic fatigue syndrome
The mechanisms and pathogenesis of chronic fatigue syndrome are unknown. Research studies examined and hypothesized about the biomedical and epidemiological characteristics of the disease, and included oxidative stress, genetic predisposition, infection by viruses and pathogenic bacteria, hypothalamic-pituitary-adrenal axis abnormalities (though it is unclear if this is a cause, or consequence, of CFS), immune dysfunction as well as mental and psychosocial factors causing or contributing to the condition. Some individuals with CFS firmly reject any psychological involvement and believe strongly that their condition has a physical cause.
The success of certain treatments suggests CFS may be perpetuated when patients fixate on a physical cause of illness, their symptoms and when exercise is avoided. Lack of support or reinforcement of illness behavior from social networks are associated with delayed recovery, as is conflict with doctors who insist on psychological causes over a patient's objections. High scores of neuroticism and introversion on psychological tests have also been linked with a predisposition to developing CFS.
Clinical descriptions of chronic fatigue syndrome
There are no medical tests or physical signs to diagnose CFS, so testing is used to rule out other potential causes for symptoms. The most widely used clinical and research description of CFS is the CDC definition published in 1994. The 1994 CDC definition, also called the Fukuda definition after the first author on the report, was based on the Holmes or CDC 1988 scoring system. The 1994 criteria require the presence of only four symptoms beyond fatigue, where the 1988 criteria require six to eight.
Other notable definitions include
The Oxford criteria (1991)
The 2003 Canadian case definition for ME/CFS was developed "in an attempt to exclude psychiatric cases." This definition requires presence of symptoms from at least one category of autonomic, neuroendocrine, or immune symptoms. Doctors with the National Health Service in the UK are discouraged from using this case definition, since requiring the presence of these signs could exclude patients, and the criteria "have not been evaluated for research purposes."
Using different case definitions may influence the types of patients selected and there is research to suggest subtypes of patients or disease exist. Clinical practice guidelines, with the aim of improving diagnosis, management, and treatment, are generally based on case descriptions. Guidelines are usually produced at national or international levels by medical associations or governmental bodies after evidence is examined and usually include summarized consensus statements. An example of a CFS guideline for the National Health Service in England and Wales, produced in 2007 by the National Institute for Health and Clinical Excellence (NICE).
Chronic fatigue syndrome treatment
Many patients do not fully recover from CFS even with treatment, and there is no universally effective curative option. Diets, physiotherapy, dietary supplements, antidepressants, pain killers, pacing, and complementary and alternative medicine have been suggested as ways of managing CFS, but the only treatments with scientifically verified benefits are cognitive behavioural therapy (CBT) and graded exercise therapy (GET). CBT and GET have both been demonstrated as effective in multiple randomized controlled trials. As many of the clinical trials require patients to visit a clinic, this may effectively exclude severely affected patients.
Cognitive behavioral therapy
Cognitive behavioral therapy (CBT), a form of psychological therapy, is a moderately effective treatment for CFS. Since the cause or causes of CFS are unknown, CBT tries to help patients understand their individual symptoms and beliefs and develop strategies to improve day-to-day functioning. CFS researcher Vincent Deary believes the CBT model of medically unexplained symptoms (MUS) has value as a heuristic for the generation of symptoms for conditions like CFS.
A Cochrane Review meta-analysis of 15 randomized, controlled cognitive behavioral therapy trials with 1043 participants concluded that CBT was an effective treatment to reduce symptoms of fatigue. Comparing CBT with "usual care," four reviewed studies showed that CBT was more effective (40% vs 26%). In three studies, CBT worked better than other types of psychological therapies (48% vs 27%). The effects may diminish after a course of therapy is completed; the reviewers write that "the evidence base at follow-up is limited to a small group of studies with inconsistent findings" and encourage further studies. Another recent meta-analysis finds improvements in randomized controlled trials ranging from 33-73%. One follow-up study of a cohort of 96 patients suggested that CBT could facilitate full recovery in some patients, with 69% no longer meeting the CDC criteria for CFS.
Graded exercise therapy
Over half of CFS patients studied experience improvements when using graded exercise therapy (GET), a form of physical therapy. Meta-analysis of multiple randomized, controlled trials of exercise therapy of patients diagnosed with CFS shows improvements in fatigue symptoms over controls. Some patient organizations dispute the results of the exercise therapy trials.
Other treatments of CFS have been proposed but their effectiveness has not been confirmed. Medications thought to have promise in alleviating stress-related disorders include antidepressant and immunomodulatory agents. Many CFS patients are sensitive to medications, particularly sedatives, and some patients report chemical and food sensitivities.
CFS patients have a low placebo response compared to patients with other diseases, possibly due to altered patient expectations regarding psychological and psychiatric expectations about their conditions.
A systematic review of 14 studies of the outcome of untreated people with CFS found that "the median full recovery rate was 5% (range 031%) and the median proportion of patients who improved during follow-up was 39.5% (range 863%). Return to work at follow-up ranged from 8 to 30% in the three studies that considered this outcome." .... "In five studies, a worsening of symptoms during the period of follow-up was reported in between 5 and 20% of patients." A good outcome was associated with less fatigue severity at baseline, a sense of control over symptoms and not attributing illness to a physical cause. Another review found that children have a better prognosis than adults, with 5494% having recovered by follow-up compared to less than 10% of adults returning to pre-morbid levels of functioning. According to the CDC, delays in diagnosis and treatment can reduce the chance of improvement.
Evidence linking CFS to early deaths is unclear. A systematic review of 14 studies of the outcome of CFS recorded 8 deaths, two were unrelated to CFS, one person died by suicide, and the circumstances of death of the other five were unclear. To date there have been two studies directly addressing life expectancy in CFS. A preliminary study of CFS self-help group members reported a greater likelihood of death at a younger than average age for cancer and suicide but another study of a much larger group with a longer follow-up found that mortality rates of individuals with CFS did not differ from the general population of the United States.
Due to the multiple definitions of CFS, estimates of its prevalence vary widely. Studies in the United States have previously found between 75 and 420 cases of CFS for every 100,000 adults. The CDC states that more than 1 million Americans have CFS and approximately 80% of the cases are undiagnosed. All ethnic and racial groups appear susceptible to the illness, and lower income groups are slightly more likely to develop CFS. More women than men get CFS between 60 and 85% of cases are women; however, there is some indication that the prevalence among men is underreported. The illness is reported to occur more frequently in people between the ages of 40 and 59. Blood relatives of people who have CFS appear to be more predisposed. There is no evidence that CFS is contagious, though it is seen in members of the same family; this is believed to be a familial or genetic link but more research is required for a definite answer.
Some diseases show a considerable overlap with CFS. Thyroid disorders, anemia, and diabetes are a few of the diseases that must be ruled out if the patient presents with appropriate symptoms.
People with fibromyalgia (FM, or fibromyalgia syndrome, FMS) have muscle pain and sleep disturbances. Fatigue and muscle pain occurs frequently in the initial phase of various hereditary muscle disorders and in several autoimmune, endocrine and metabolic syndromes; and are frequently labelled as CFS or fibromyalgia in the absence of obvious biochemical/metabolic abnormalities and neurological symptoms. Multiple chemical sensitivity, Gulf War syndrome and post-polio syndrome have symptoms similar to those of CFS, and the latter is also theorized to have a common pathophysiology.
Although post-Lyme syndrome and CFS share many features/symptoms, a study found that patients of the former experience more cognitive impairment and the patients of the latter experience more flu-like symptoms.
A 2006 review found that there was a lack of literature to establish the discriminant validity of undifferentiated somatoform disorder from CFS. The author stated that there is a need for proponents of chronic fatigue syndrome to distinguish it from undifferentiated somatoform disorder. The author also mentioned that the experience of fatigue as exclusively physical and not mental is captured by the definition of somatoform disorder but not CFS. Hysterical diagnoses are not merely diagnoses of exclusion but require criteria to be met on the positive grounds of both primary and secondary gain. Primary depression can be excluded in the differential diagnosis due to the absence of anhedonia and la belle indifference, the variability (lability) of mood, and the presence of sensory phenomena and somatic signs such as ataxia, myclonus and most importantly, exercise intolerance with paresis, malaise and general deterioration. Feeling depressed is also a commonplace reaction to the losses caused by chronic illness which can in some cases become a comorbid situational depression.
Many CFS patients will also have, or appear to have, other medical problems or related diagnoses. Co-morbid fibromyalgia is common, where only patients with fibromyalgia show abnormal pain responses. Fibromyalgia occurs in a large percentage of CFS patients between onset and the second year, and some researchers suggest fibromyalgia and CFS are related. As previously mentioned, many CFS sufferers also experience symptoms of irritable bowel syndrome, temporomandibular joint pain, headache including migraines, and other forms of myalgia. CFS patients have significantly higher rates of current mood disorders than the general population. Compared with the non-fatigued population, male CFS patients are more likely to experience chronic pelvic pain syndrome (CP/CPPS), and female CFS patients are also more likely to experience chronic pelvic pain. CFS is significantly more common in women with endometriosis compared with women in the general USA population.
History of chronic fatigue syndrome
In 1934 there was an outbreak of a condition then referred to as atypical poliomyelitis at the Los Angeles County Hospital. Strongly resembling what is now called chronic fatigue syndrome and affecting a large number of nurses and doctors, at the time it was considered a form of polio. In 1955 at the Royal Free Hospital in London, United Kingdom, another outbreak occurred that also affected mostly the hospital staff. Also resembling CFS, it was called both Royal Free disease and benign myalgic encephalomyelitis and formed the basis of descriptions by Achenson, Ramsay, and others. In 1969 benign myalgic encephalomyelitis was first classified into the International Classification of Diseases under Diseases of the nervous system.
The name chronic fatigue syndrome was proposed in the 1988 article, "Chronic fatigue syndrome: a working case definition", (the Holmes definition), to replace chronic Epstein-Barr virus syndrome. This research case definition was published after US Centers for Disease Control and Prevention epidemiologists examined patients at the Lake Tahoe outbreak. In 2006 the CDC commenced a public awareness program.
Society and culture
Many patients report that a chronic fatigue syndrome diagnosis carries a considerable social stigma, and has frequently been viewed as malingering, hypochondriasis, phobia, "wanting attention" or "yuppie flu". As there is no medical test to diagnose CFS, it has been argued that it is easy to invent or feign CFS-like symptoms for financial, social, or emotional benefits. CFS sufferers argue in turn that the perceived "benefits" are hardly as generous as some may believe, and that CFS patients would greatly prefer to be healthy and independent. The Australian 2002 clinical practice guidelines for CFS state that "In the absence of evidence of malingering, speculative judgements about unconscious motivation should be avoided; the psychoanalytic concept of 'secondary gain' has been misused in medicolegal settings and does not rest on a solid empirical base."
A study found that CFS patients endure a heavy psychosocial burden. 2,338 respondents of a survey by a UK patient organization highlights that those with the worst symptoms often receive the least support from health and social services. A study found that CFS patients receive worse social support than disease-free cancer patients or healthy controls, which may perpetuate fatigue severity and functional impairment in CFS. A survey by the Thymes Trust found that children with CFS often state that they struggle for recognition of their needs and/or they feel bullied by medical and educational professionals. The ambiguity of the status of CFS as a medical condition may cause higher perceived stigma. A study suggests that while there are no gender differences in CFS symptoms, men and women have different perceptions of their illness and are treated differently by the medical profession. Anxiety and depression often result from the emotional, social and financial crises caused by CFS; analysis of the deaths of individuals with CFS found that suicide is one of the three most prevalent causes, and the mean age of suicide is much younger than that of the remainder of the population.
Some in the medical community did not at first recognize CFS as a real condition, nor was there agreement on its prevalence. There has been much disagreement over proposed causes, diagnosis, and treatment of the illness. The context of contested causation may affect the lives of the individuals diagnosed with CFS, affecting the patient-doctor relationship, the doctor's confidence in their ability to diagnose and treat, ability to share issues and control in diagnosis with the patient, and raise problematic issues of reparation, compensation, and blame. The etiology is unknown and a major divide exists over whether funding for research and treatment should focus on physiological, psychological or psychosocial aspects of CFS. The division is especially great between patient groups and psychological and psychosocial treatment advocates in Great Britain. Sufferers describe the struggle for healthcare and legitimacy due to bureaucratic denial of the condition because of its lack of a known etiology. Disagreements over how the condition is dealt with by health care systems has resulted in an expensive and prolonged conflict for all involved.
Alternative names for chronic fatigue syndrome
Selecting a name for CFS has been challenging, since consensus is lacking within the clinical, research, and patient communities regarding its defining features and causes. Different authorities on the illness view CFS as a central nervous system, metabolic, infectious or post-infectious, cardiovascular, immune system or psychiatric disorder, and also consider the possibility that it is not a single homogenous disorder with a range of possible clinical presentations, but a group of several distinct disorders with many clinical characteristics in common.
Over time and in different countries many names have been associated with the condition(s). Aside from CFS, some other names used include Akureyri disease, benign myalgic encephalomyelitis, chronic fatigue immune dysfunction syndrome, chronic infectious mononucleosis, epidemic myalgic encephalomyelitis, epidemic neuromyasthenia, Iceland disease, myalgic encephalomyelitis, myalgic encephalitis, myalgic encephalopathy, post-viral fatigue syndrome, raphe nucleus encephalopathy, Royal Free disease, Tapanui flu and yuppie flu (now considered pejorative). Many patients particularly prefer what they feel is a more "medical-sounding" term, such as "chronic fatigue immune dysfunction syndrome" (CFIDS) or "myalgic encephalomyelitis" (ME), believing the name "chronic fatigue syndrome" trivializes the condition and prevents it from being seen as a serious health problem.
A 2001 review referenced symptoms described by a 1959 myalgic encephalomyelitis article by Acheson, stating ME could be a distinct syndrome from CFS, but in literature CFS and ME are usually regarded as the same illness. Researchers have questioned the accuracy of the term "myalgic encephalomyelitis" as there is "no recognized pathology in muscles and in the central nervous system." For this reason, in 1996 the Royal Colleges of Physicians, Psychiatrists, and General Practitioners in the United Kingdom recommended the use of chronic fatigue syndrome instead of myalgic encephalomyelitis. The report received some acceptance, but also harsh criticism that patients' views had been excluded. In 2002, a Lancet commentary cited a newly published report from the "Working Group on CFS/ME" explaining, "The fact that both names for the illness were used symbolises respect for different viewpoints whilst acknowledging the continuing lack of consensus on a universally acceptable name.".
^ a b c Evangard B, Schacterie R.S., Komaroff A. L. (1999). "Chronic fatigue syndrome: new insights and old ignorance". Journal of Internal Medicine Nov;246 (5): 455469. doi:10.1046/j.1365-2796.1999.00513.x. PMID 10583715. http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-2796.1999.00513.x.
Retrieved on 2008-11-03.
^ Ranjith G (2005). "Epidemiology of chronic fatigue syndrome.". Occup Med (Lond) 55 (1): 1329. doi:10.1093/occmed/kqi012. PMID 15699086.
^ a b c d Wyller VB (2007). "The chronic fatigue syndrome--an update". Acta neurologica Scandinavica. Supplementum 187: 714. doi:10.1111/j.1600-0404.2007.00840.x. PMID 17419822.
^ a b Afari N, Buchwald D (2003). "Chronic fatigue syndrome: a review". Am J Psychiatr 160 (2): 22136. doi:10.1176/appi.ajp.160.2.221. PMID 12562565. http://ajp.psychiatryonline.org/cgi/content/full/160/2/221.
^ a b c d e f "Chronic Fatigue Syndrome Basic Facts" (htm). Centers for Disease Control and Prevention. May 9, 2006. http://www.cdc.gov/cfs/cfsbasicfacts.htm.
Retrieved on 2008-02-07.
^ Jason LA et al. (1999). "A community-based study of chronic fatigue syndrome". Arch. Intern. Med. 159 (18): 212937. doi:10.1001/archinte.159.18.2129. PMID 10527290. http://archinte.ama-assn.org/cgi/content/full/159/18/2129.
^ Gallagher AM, Thomas JM, Hamilton WT, White PD (2004). "Incidence of fatigue symptoms and diagnoses presenting in UK primary care from 1990 to 2001". J R Soc Med 97 (12): 5715. doi:10.1258/jrsm.97.12.571. PMID 15574853.
^ a b c "Chronic Fatigue Syndrome Who's at risk?". Centers for Disease Control and Prevention. March 10, 2006. http://www.cdc.gov/cfs/cfscausesHCP.htm.
Retrieved on 2008-02-07.
^ Farmer A, Fowler T, Scourfield J, Thapar A (June 2004). "Prevalence of chronic disabling fatigue in children and adolescents". Br J Psychiatry 184: 47781. doi:10.1192/bjp.184.6.477. PMID 15172940. http://bjp.rcpsych.org/cgi/pmidlookup?view=long&pmid=15172940.
^ a b Ross SD, Estok RP, Frame D, Stone LR, Ludensky V, Levine CB (2004). "Disability and chronic fatigue syndrome: a focus on function.". Arch Intern Med 164 (10): 1098107. doi:10.1001/archinte.164.10.1098. PMID 15159267. http://archinte.ama-assn.org/cgi/content/full/164/10/1098.
^ a b Salit IE (1997). "Precipitating factors for the chronic fatigue syndrome.". J Psychiatr Res 31 (1): 5965. doi:10.1016/S0022-3956(96)00050-7. PMID 9201648.
^ Jason LA, Taylor RR, Carrico AW (2001). "A community-based study of seasonal variation in the onset of chronic fatigue syndrome and idiopathic chronic fatigue.". Chronobiol Int 18 (2): 3159. doi:10.1081/CBI-100103194. PMID 11379670.
^ Zhang QW, Natelson BH, Ottenweller JE, Servatius RJ, Nelson JJ, De Luca J, Tiersky L, Lange G (2000). "Chronic fatigue syndrome beginning suddenly occurs seasonally over the year.". Chronobiol Int 17 (1): 959. doi:10.1081/CBI-100101035. PMID 10672437.
^ Hatcher S, House A (2003). "Life events, difficulties and dilemmas in the onset of chronic fatigue syndrome: a case-control study." (PDF). Psychol Med 33 (7): 118592. doi:10.1017/S0033291703008274. PMID 14580073. http://eprints.whiterose.ac.uk/1226/1/house3.pdf.
^ Theorell T, Blomkvist V, Lindh G, Evengard B. "Critical life events, infections, and symptoms during the year preceding chronic fatigue syndrome (CFS): an examination of CFS patients and subjects with a nonspecific life crisis.". Psychosom Med. 61 (3): 30410. PMID 10367610.
^ Hickie I, Davenport T, Wakefield D, et al (2006). "Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: prospective cohort study". BMJ 333 (7568): 575. doi:10.1136/bmj.38933.585764.AE. PMID 16950834.
^ a b "Chronic Fatigue Syndrome: Diagnosing CFS". CDC. 2006-05-03. http://www.cdc.gov/cfs/cfsdiagnosis.htm.
Retrieved on 2009-01-22.
^ McCully KK, Sisto SA, Natelson BH (1996). "Use of exercise for treatment of chronic fatigue syndrome.". Sports Med 21 (1): 3548. doi:10.2165/00007256-199621010-00004. PMID 8771284.
^ Solomon L, Nisenbaum R, Reyes M, Papanicolaou DA, Reeves WC (2003). "Functional status of persons with chronic fatigue syndrome in the Wichita, Kansas, population.". Health Qual Life Outcomes 1 (1): 4858. doi:10.1186/1477-7525-1-48. PMID 14577835. Full text at PMC: 239865
^ "Chronic Fatigue Syndrome: Clinical Course". Centers for Disease Control and Prevention. 2006-05-09. http://www.cdc.gov/cfs/cfssymptomsHCP.htm#clinical.
Retrieved on 2009-01-15.
^ Ho-Yen DO, McNamara I (1991). "General practitioners' experience of the chronic fatigue syndrome". Br J Gen Pract 41 (349): 3246. PMID 1777276.
^ Meeus M, Nijs J, Meirleir KD (2007). "Chronic musculoskeletal pain in patients with the chronic fatigue syndrome: A systematic review.". Eur J Pain 11 (4): 377386. doi:10.1016/j.ejpain.2006.06.005. PMID 16843021.
^ Vanness JM, Snell CR, Strayer DR, Dempsey L 4th, Stevens SR (2003). "Subclassifying chronic fatigue syndrome through exercise testing.". Med Sci Sports Exerc 35 (6): 90813. doi:10.1249/01.MSS.0000069510.58763.E8. PMID 12783037.
^ Sanders P, Korf J (2007). "Neuroaetiology of chronic fatigue syndrome: An overview". World J Biol Psychiatry 9: 17. doi:10.1080/15622970701310971. PMID 17853290. http://www.informaworld.com/openurl?genre=article&doi=10.1080/15622970701310971&magic=pubmed.
^ Vercoulen JH, Swanink CM, Galama JM, et al (1998). "The persistence of fatigue in chronic fatigue syndrome and multiple sclerosis: development of a model". J Psychosom Res 45 (6): 50717. doi:10.1016/S0022-3999(98)00023-3. PMID 9859853.
^ a b Cho HJ, Hotopf M, Wessely S (2005). "The placebo response in the treatment of chronic fatigue syndrome: a systematic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME)". Psychosom Med 67 (2): 30113. doi:10.1097/01.psy.0000156969.76986.e0. PMID 15784798. http://www.psychosomaticmedicine.org/cgi/content/full/67/2/301.
Retrieved on 2008-12-12.
^ a b Prins JB, Bos E, Huibers MJ, Servaes P, van der Werf SP, van der Meer JW, Bleijenberg G (2004). "Social support and the persistence of complaints in chronic fatigue syndrome.". Psychother Psychosom 73 (3): 17482. doi:10.1159/000076455. PMID 15031590.
^ a b c d e Prins JB, van der Meer JW, Bleijenberg G (2006). "Chronic fatigue syndrome". Lancet 367 (9507): 34655. doi:10.1016/S0140-6736(06)68073-2. PMID 16443043.
^ a b c Fukuda K, Straus S, Hickie I, Sharpe M, Dobbins J, Komaroff A (15 Dec 1994). "The chronic fatigue syndrome: a comprehensive approach to its definition and study. International Chronic Fatigue Syndrome Study Group.". Ann Intern Med 121 (12): 9539. PMID 7978722. http://www.annals.org/cgi/content/full/121/12/953.
^ a b Holmes G, Kaplan J, Gantz N, Komaroff A, Schonberger L, Straus S, Jones J, Dubois R, Cunningham-Rundles C, Pahwa S (1988). "Chronic fatigue syndrome: a working case definition,". Ann Intern Med 108 (3): 3879. PMID 2829679. Details
^ a b c d Guideline 53: Chronic fatigue syndrome/myalgic encephalomyelitis (or encephalopathy). London: = National Institute for Health and Clinical Excellence. 2007. ISBN 1846294533. http://guidance.nice.org.uk/CG53.
^ Sharpe M, Archard L, Banatvala J, Borysiewicz L, Clare A, David A, Edwards R, Hawton K, Lambert H, Lane R (1991). "A report--chronic fatigue syndrome: guidelines for research". J R Soc Med 84 (2): 11821. PMID 1999813. Full text at PMC: 1293107 Synopsis by Oxford criteria for the diagnosis of chronic fatigue syndrome at GPnotebook)
^ Carruthers BM, et al. (2003). "Myalgic encephalomyalitis/chronic fatigue syndrome: Clinical working definition, diagnostic and treatment protocols" (PDF). Journal of Chronic Fatigue Syndrome 11 (1): 736. doi:10.1300/J092v11n01_02. http://www.cfids-cab.org/MESA/ccpccd.pdf.
^ Wearden AJ, Riste L, Dowrick C, Chew-Graham C, Bentall RP, Morriss RK, Peters S, Dunn G, Richardson G, Lovell K, Powell P (2006). "Fatigue Intervention by Nurses Evaluation - The FINE Trial. A randomised controlled trial of nurse led self-help treatment for patients in primary care with chronic fatigue syndrome: study protocol". BMC Med 4 (9): 9. doi:10.1186/1741-7015-4-9. PMID 16603058.
^ Reeves WC, Lloyd A, Vernon SD, Klimas N, Jason LA, Bleijenberg G, Evengard B, White PD, Nisenbaum R, Unger ER (2003). "Identification of ambiguities in the 1994 chronic fatigue syndrome research case definition and recommendations for resolution.". BMC Health Serv Res 3 (1): 25. doi:10.1186/1472-6963-3-25. PMID 14702202.
^ Jason LA, Corradi K, Torres-Harding S, Taylor RR, King C (2005). "Chronic fatigue syndrome: the need for subtypes.". Neuropsychol Rev 15 (1): 2958. doi:10.1007/s11065-005-3588-2. PMID 15929497.
^ Whistler T, Unger ER, Nisenbaum R, Vernon SD (December 2003). "Integration of gene expression, clinical, and epidemiologic data to characterize Chronic Fatigue Syndrome". J Transl Med 1 (1): 10. doi:10.1186/1479-5876-1-10. PMID 14641939.
^ Kennedy G, Abbot NC, Spence V, Underwood C, Belch JJ (February 2004). "The specificity of the CDC-1994 criteria for chronic fatigue syndrome: comparison of health status in three groups of patients who fulfill the criteria". Ann Epidemiol 14 (2): 95100. doi:10.1016/j.annepidem.2003.10.004. PMID 15018881.
^ Aslakson E, Vollmer-Conna U, White PD (April 2006). "The validity of an empirical delineation of heterogeneity in chronic unexplained fatigue". Pharmacogenomics 7 (3): 36573. doi:10.2217/146224126.96.36.1995. PMID 16610947.
^ Rimes KA, Chalder T. (2005). "Treatments for chronic fatigue syndrome.". Occupational Medicine 55 (1): 3239. doi:10.1093/occmed/kqi015. PMID 15699088.
^ a b c Chambers D, Bagnall AM, Hempel S, Forbes C (2006). "Interventions for the treatment, management and rehabilitation of patients with chronic fatigue syndrome/myalgic encephalomyelitis: an updated systematic review". Journal of the Royal Society of Medicine 99 (10): 50620. doi:10.1258/jrsm.99.10.506. PMID 17021301.
^ Raine R, Haines A, Sensky T, Hutchings A, Larkin K, Black N (2002). "Systematic review of mental health interventions for patients with common somatic symptoms: can research evidence from secondary care be extrapolated to primary care?". BMJ 325 (7372): 1082. doi:10.1136/bmj.325.7372.1082. PMID 12424170.
^ a b Whiting P, Bagnall AM, Sowden AJ, Cornell JE, Mulrow CD, Ramirez G (September 2001). "Interventions for the treatment and management of chronic fatigue syndrome: a systematic review". JAMA 286 (11): 13608. doi:10.1001/jama.286.11.1360. PMID 11560542. http://jama.ama-assn.org/cgi/content/full/286/11/1360.
^ Reid S, Chalder T, Cleare A, Hotopf M, Wessely S. (2000). "Chronic fatigue syndrome". BMJ 320 (7230): 2926. doi:10.1136/bmj.320.7230.292. PMID 10650029.
^ a b Malouff JM, et al. (June 2008). "Efficacy of cognitive behavioral therapy for chronic fatigue syndrome: a meta-analysis". Clin Psychol Rev 28 (5): 73645. doi:10.1016/j.cpr.2007.10.004. PMID 18060672.
^ Wolfe F; Chalmers A; Littlejohn GO & Salit I (1995). Fibromyalgia, Chronic Fatigue Syndrome, and Repetitive Strain Injury: Current Concepts in Diagnosis, Management, Disability, and Health Economics. New York: Haworth Medical Press. pp. 142. ISBN 1-56024-744-4. http://books.google.com/books?id=Da0jf7agNvgC&pg=PA142.
^ Deary V, Chalder T, Sharpe M (October 2007). "The cognitive behavioural model of medically unexplained symptoms: a theoretical and empirical review". Clin Psychol Rev 27 (7): 78197. doi:10.1016/j.cpr.2007.07.002. PMID 17822818.
^ Price JR, Mitchell E, Tidy E, Hunot V (2008). "Cognitive behaviour therapy for chronic fatigue syndrome in adults". Cochrane Database Syst Rev (3): CD001027. doi:10.1002/14651858.CD001027.pub2. PMID 18646067.
^ Knoop H, Bleijenberg G, Gielissen MF, van der Meer JW, White PD (2007). "Is a full recovery possible after cognitive behavioural therapy for chronic fatigue syndrome?". Psychother Psychosom 76 (3): 1716. doi:10.1159/000099844. PMID 17426416.
^ Edmonds M, McGuire H, Price J (2004). "Exercise therapy for chronic fatigue syndrome". Cochrane Database Syst Rev (3): CD003200. doi:10.1002/14651858.CD003200.pub2. PMID 15266475.
^ White PD, Sharpe MC, Chalder T, DeCesare JC, Walwyn R (2007). "Protocol for the PACE trial: a randomised controlled trial of adaptive pacing, cognitive behaviour therapy, and graded exercise, as supplements to standardised specialist medical care versus standardised specialist medical care alone for patients with the chronic fatigue syndrome/myalgic encephalomyelitis or encephalopathy". BMC Neurol 7: 6. doi:10.1186/1471-2377-7-6. PMID 17397525. http://www.biomedcentral.com/1471-2377/7/6.
^ Covelli V, Passeri ME, Leogrande D, Jirillo E, Amati L (2005). "Drug targets in stress-related disorders". Curr. Med. Chem. 12 (15): 18019. doi:10.2174/0929867054367202. PMID 16029148.
^ National Center for Infectious Diseases (2005-05-11). "Treatment of Patients with Chronic Fatigue Syndrome". Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/diseases/cfs/treat.htm.
Retrieved on 2008-04-07.
^ a b Cairns R, Hotopf M (2005). "A systematic review describing the prognosis of chronic fatigue syndrome". Occupational medicine (Oxford, England) 55 (1): 2031. doi:10.1093/occmed/kqi013. PMID 15699087. http://occmed.oxfordjournals.org/cgi/reprint/55/1/20.
^ Joyce J, Hotopf M, Wessely S. (1997). "The prognosis of chronic fatigue and chronic fatigue syndrome: a systematic review.". QJM 90 (3): 22333. doi:10.1093/qjmed/90.3.223. PMID 9093600.
^ "CFS Toolkit for Health Care Professionals: Basic CFS Overview" (PDF file, 31 KB). U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. http://www.cdc.gov/cfs/pdf/Basic_Overview.pdf.
Retrieved on 2008-03-19.
^ a b Jason LA, Corradi K, Gress S, Williams S, Torres-Harding S (2006). "Causes of death among patients with chronic fatigue syndrome". Health care for women international 27 (7): 61526. doi:10.1080/07399330600803766. PMID 16844674.
^ Smith WR, Noonan C, Buchwald D (2006). "Mortality in a cohort of chronically fatigued patients". Psychological medicine 36 (9): 13016. doi:10.1017/S0033291706007975. PMID 16893495.
^ Walsh CM, Zainal NZ, Middleton SJ, Paykel ES (2001). "A family history study of chronic fatigue syndrome.". Psychiatr Genet 11 (3): 1238. doi:10.1097/00041444-200109000-00003. PMID 11702053.
^ "Chronic Fatigue Syndrome: Who's at Risk?". Centers for Disease Control and Prevention. May 3, 2006. http://www.cdc.gov/cfs/cfsatrisk.htm.
Retrieved on 2008-12-12.
^ Craig, T and Kakumanu S (Mar 2002). "Chronic fatigue syndrome: evaluation and treatment". Am Fam Physician. 65 (6): 108390. PMID 11925084. http://www.aafp.org/afp/20020315/1083.html.
^ Vojdani A, Thrasher J (2004). "Cellular and humoral immune abnormalities in Gulf War veterans.". Environ Health Perspect 112 (8): 8406. doi:10.1289/ehp.6881. PMID 15175170.
^ a b Bruno RL, Creange SJ, Frick NM (1998). "Parallels between post-polio fatigue and chronic fatigue syndrome: a common pathophysiology?". Am J Med. 105 (3A): 66S73S. doi:10.1016/S0002-9343(98)00161-2. PMID 9790485.
^ Gaudino EA, Coyle PK, Krupp LB (1997). "Post-Lyme syndrome and chronic fatigue syndrome. Neuropsychiatric similarities and differences.". Arch Neurol 54 (11): 13726. PMID 9362985.
^ van Staden WC (2006). "Conceptual issues in undifferentiated somatoform disorder and chronic fatigue syndrome.". Curr Opin Psychiatry 19 (6): 6138. PMID 17012941.
^ Jenkins R, Mowbray J, ed. Post-viral Fatigue Syndrome. 1991 John Wiley & Sons Ltd
^ Frank RG, Chaney JM, Clay DL, Shutty MS, Beck NC, Kay DR, Elliott TR, Grambling S (1992). "Dysphoria: a major symptom factor in persons with disability or chronic illness.". Psychiatry Res 43 (3): 23141. doi:10.1016/0165-1781(92)90056-9. PMID 1438622.
^ Bradley LA, McKendree-Smith NL, Alarcon GS (2000). "Pain complaints in patients with fibromyalgia versus chronic fatigue syndrome.". Curr Rev Pain 4 (2): 14857. PMID 10998728.
^ Friedberg F, Jason LA (2001). "Chronic fatigue syndrome and fibromyalgia: clinical assessment and treatment.". J Clin Psychol. 57 (4): 43355. doi:10.1002/jclp.1040. PMID 11255201.
^ Prins J, Bleijenberg G, Rouweler EK, van der Meer J. (2005). "Effect of psychiatric disorders on outcome of cognitive-behavioural therapy for chronic fatigue syndrome.". Br J Psychiatry 187: 1845. doi:10.1192/bjp.187.2.184. PMID 16055833.
^ Aaron LA, Herrell R, Ashton S, Belcourt M, Schmaling K, Goldberg J, Buchwald D (2001). "Comorbid clinical conditions in chronic fatigue: a co-twin control study.". J Gen Intern Med 16 (1): 2431. doi:10.1111/j.1525-1497.2001.03419.x. PMID 11251747. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11251747.
^ Sinaii N, Cleary SD, Ballweg ML, Nieman LK, Stratton P (2002). "High rates of autoimmune and endocrine disorders, fibromyalgia, chronic fatigue syndrome and atopic diseases among women with endometriosis: a survey analysis.". Hum Reprod 17 (10): 271524. doi:10.1093/humrep/17.10.2715. PMID 12351553.
^ Patarca-Montero R (2004). Medical Etiology, Assessment, and Treatment of Chronic Fatigue and Malaise. Haworth Press. pp. 67. ISBN 078902196X.
^ "AN OUTBREAK of encephalomyelitis in the Royal Free Hospital Group, London, in 1955". Br Med J 2 (5050): 895904. 1957. doi:10.1136/bmj.2.5050.895. PMID 13472002. http://books.google.com/books?id=QNqC7DUdJRsC&pg=PA7&lpg=PA7.
^ International Classification of Diseases, I, World Health Organization, 1969, pp. 158, (vol 2, pp. 173)
^ Sharpe M & Campling F (2000). Chronic Fatigue Syndrome (CFS/ME): TheFacts. Oxford: Oxford Press. pp. 14,15. ISBN 0-19-263049-0. http://books.google.com/books?id=_LqAIK616lgC&pg=PA14.
Retrieved on 2008-04-02.
^ Packard RM, Berkelman RL, Brown PJ, Frumkin H (2004). Emerging Illnesses and Society. JHU Press. pp. 156. ISBN 0801879426. http://books.google.com/books?id=EGNFPZrKIKMC&pg=PA156.
Retrieved on 2008-04-02.
^ Rogers, Richard (1997). Clinical Assessment of Malingering and Deception, Second Edition. New York, London: Guilford Press. pp. 40. ISBN 1572301732. http://books.google.com/books?id=YZ6uK4Cjd_MC&pg=PA40.
^ Malleson, Andrew (2005). Whiplash and Other Useful Illnesses. Quebec: McGill-Queen's Press. pp. 59. ISBN 0773529942. http://books.google.com/books?id=naDghccZhEwC&pg=PA59.
^ Working Group of the Royal Australasian College of Physicians (2002). "Chronic fatigue syndrome. Clinical practice guidelines--2002.". Med J Aust 176: Suppl:S2356. PMID 12056987. http://www.mja.com.au/public/guides/cfs/cfs2.html.
^ Van Houdenhove B, Neerinckx E, Onghena P, Vingerhoets A, Lysens R, Vertommen H (2002). "Daily hassles reported by chronic fatigue syndrome and fibromyalgia patients in tertiary care: a controlled quantitative and qualitative study.". Psychother Psychosom 71 (4): 20713. doi:10.1159/000063646. PMID 12097786.
^ Action for M.E. in the UK, Severely Neglected: Membership Survey London: Action for M.E.; 2001
^ Colby J (2007). "Special problems of children with myalgic encephalomyelitis/chronic fatigue syndrome and the enteroviral link.". J Clin Pathol 60 (2): 1258. doi:10.1136/jcp.2006.042606. 16935964. PMID 16935964.
^ Looper KJ, Kirmayer LJ (2004). "Perceived stigma in functional somatic syndromes and comparable medical conditions.". J Psychosom Res 57 (4): 3738. PMID 15518673.
^ Clarke JN (1999). "Chronic fatigue syndrome: gender differences in the search for legitimacy.". Aust N Z J Ment Health Nurs 8 (4): 12333. doi:10.1046/j.1440-0979.1999.00145.x. PMID 10855087.
^ Wallace, PG (October 1991). "Post-viral fatigue syndrome. Epidemiology: a critical review". Br Med Bull. 47 (4): 942951. PMID 1794092.
^ a b Mounstephen, A,; Sharpe M. (May 1997). "Chronic fatigue syndrome and occupational health". Occup Med (Lond). May;47(4):. 47 (4): 217227. doi:10.1093/occmed/47.4.217. PMID 1794092.
^ Hooge J (1992). "Chronic fatigue syndrome: cause, controversy and care". Br J Nurs 1 (9): 4401, 443, 4456. PMID 1446147.
^ Sharpe M (1996). "Chronic fatigue syndrome". Psychiatr. Clin. North Am. 19 (3): 54973. doi:10.1016/S0193-953X(05)70305-1. PMID 8856816.
^ Denz-Penhey H, Murdoch JC (1993). "General practitioners acceptance of the validity of chronic fatigue syndrome as a diagnosis". N. Z. Med. J. 106 (953): 1224. PMID 8474729.
^ Greenlee JE, Rose JW (2000). "Controversies in neurological infectious diseases". Semin Neurol 20 (3): 37586. doi:10.1055/s-2000-9429. PMID 11051301.
^ a b Horton-Salway M (2007). "The ME Bandwagon and other labels: constructing the genuine case in talk about a controversial illness". Br J Soc Psychol 46 (Pt 4): 895914. doi:10.1348/014466607X173456. PMID 17535450.
^ Engel CC, Adkins JA, Cowan DN (2002). "Caring for medically unexplained physical symptoms after toxic environmental exposures: effects of contested causation". Environ. Health Perspect. 110 Suppl 4: 6417. PMID 12194900.
^ Dumit, J. (2005-08-08). "Illnesses you have to fight to get: facts as forces in uncertain, emergent illnesses.". Soc Sci Med. Feb;62 (3): 57790. PMID 16085344.
^ NORD (June 23, 2008). "Chronic Fatigue Syndrome/Myalgic Encephalomyelitis" (html). National Organization for Rare Disorders, Inc.. http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Chronic%20Fatigue%20Syndrome/Myalgic%20Encephalomyelitis.
Retrieved on 2008-07-01.
^ Donoghue, PJ; Siegel ME (1992). Sick And Tired Of Feeling Sick And Tired: Living with Invisible Chronic Illness. W. W. Norton & Company. pp. 15. ISBN 0393034089. http://books.google.ca/books?id=8r1dnOxPwdEC&pg=PA15.
Retrieved on 2008-09-17.
^ "About CFIDS". CFIDS Association of America. http://www.cfids.org/about-cfids/default.asp.
Retrieved on 2008-10-23.
^ Sharpe M (2002). "The report of the Chief Medical Officer's CFS/ME working group: what does it say and will it help?". Clin Med 2 (5): 4279. PMID 12448589.
^ Tuller, D (2007-07-17). "Chronic Fatigue Syndrome No Longer Seen as "Yuppie Flu"". The New York Times. http://www.nytimes.com/2007/07/17/science/17fatigue.html.
Retrieved on 2008-10-23.
^ "The Psychiatry Research Trust - Chronic Fatigue Syndrome". http://www.iop.kcl.ac.uk/iop/PRT/cfs.htm.
Retrieved on 2008-11-30.
^ Royal Colleges of Physicians, Psychiatrists and General Practitioners (1996). Chronic fatigue syndrome; Report of a joint working group of the Royal Colleges of Physicians, Psychiatrists and General Practitioners. London, UK: Royal College of Physicians of London. ISBN 1-86016-046-8.
^ "Report of the Working Party on CSF/ME to the Chief Medical Officer for England and Wales" (pdf). Department of Health. January 2002. http://web.archive.org/web/20030322075848/http://www.doh.gov.uk/cmo/cfsmereport/cfsmereport.pdf.
Retrieved on 2009-01-25.
^ Clark C, Buchwald D, MacIntyre A, Sharpe M, Wessely S (January 2002). "Chronic fatigue syndrome: a step towards agreement". Lancet 359 (9301): 978. doi:10.1016/S0140-6736(02)07336-1. PMID 11809249. http://linkinghub.elsevier.com/retrieve/pii/S0140673602073361.
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