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Chronic fatigue syndrome/myalgic encephalomyelitis: more heat, some light—directions for research and clinical practice
  1. Richard Morriss
  1. Correspondence to Professor Richard Morriss, B Floor, Institute of Mental Health, University of Nottingham Innovation Park, Triumph Road, Nottingham NG7 2DU, UK; richard.morriss{at}

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Under proper supervision first-line treatments for chronic fatigue syndrome are effective and safe but research into second-line treatment is required.

In the paper by Smith and Wessely,1 problems are outlined in commissioning services in Scotland2 that accommodate the acrimonious debate between the views of those who consider myalgic encephalomyelitis (ME) to be a neurological condition versus an evidence-based medicine view that chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a condition of uncertain aetiology improved by graded exercise treatment (GET) and cognitive behaviour therapy (CBT).3 The debate threatens to hinder the development of safe, cost-effective and clinically effective services for patients with CFS/ME, and to stifle further research building on important discoveries on diagnosis, the limited effectiveness of current treatments and the validity of ‘objective’ outcome measures.

A wide range of diagnostic criteria are used in research and clinical practice2–7 that differ in terms of duration of chronic fatigue as a central symptom (3, 4 or 6 months), the requirement or not for postexertional fatigue lasting more than 24 h, additional symptoms or diagnoses of exclusion. Factors such as number of symptoms and postexertional malaise did not predict outcome in recent large randomised controlled trials (RCTs) in primary and secondary care, although depression symptoms and duration may do.8–10 Moreover, most patients meeting research criteria for CFS would also meet research criteria for other ill-defined conditions treated in other specialist clinics such as fibromyalgia, irritable bowels syndrome, non-cardiac chest pain cross-sectionally and over time.11 ,12 Thus differences in specific diagnostic criteria for CFS/ME may reflect current referral patterns, symptom presentation, illness beliefs13 and physiological state.

The Pacing, graded Activity and Cognitive behaviour therapy (PACE): a randomised evaluation8 in 641 patients with CFS demonstrated that CBT and GET given by specially trained and supervised therapists were more effective than adaptive pacing therapy or specialist medical care alone in fatigue, function and postexertional malaise with few adverse effects, confirming previous meta-analysis.3 The results differed little with more restrictive criteria for CFS although only GET improved exercise capacity. Nevertheless, only 30% of patients recovered back to normal fatigue and physical function with CBT and GET, and it is unclear how many severely disabled patients with CFS/ME were included.

Given the discrepancy between patient report of harm from exercise given by non-specialist therapists and the lack of adverse effects of exercise in RCTs involving specialist therapists,3 ,8 ,9 graded exercise for moderate or severe CFS/ME should be given only by adequately trained and supervised therapists with experience of managing CFS/ME.13 This may be costly to implement.14 In more severe CFS/ME, there is often medical and mental comorbidity3–13 as well as physiological complications such as orthostatic hypotension and tachycardia, possibly due to deconditioning, which may impair exercise tolerance and function.15 ,16

In summary, GET and CBT are effective and safe in CFS/ME when given by trained and supervised specialist therapists but research is required into alternative or more intensive treatments for those who do not recover with GET and CBT, or have severe CFS/ME. Such RCTs should not use exercise capacity on a treadmill as a primary outcome measure17 as improvement in exercise capacity is neither necessary nor sufficient for symptomatic and functional improvement.8


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  • Contributors RM planned, conducted and wrote the submitted editorial commentary. He is the guarantor of the editorial commentary.

  • Funding RM is currently funded as part of the CLAHRC Nottinghamshire, Derbyshire and Lincolnshire; he is also funded by a central grant from the National Institute of Health Research (NIHR) and further funding from Nottinghamshire Healthcare Trust, University of Nottingham, other NHS Trusts in CLAHRC. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

  • Competing interests RM has received funding from the UK Medical Research Council, the NHS and the Linbury Trust to carry out randomised controlled trials of graded exercise and rehabilitation in CFS/ME.

  • Provenance and peer review Commissioned; internally peer reviewed.

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