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Tackling fears about exercise is important for ME treatment, analysis indicates

BMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h227 (Published 14 January 2015) Cite this as: BMJ 2015;350:h227

The cognitive-behavioural model of illness for chronic fatigue syndrome and myalgic encephalomyelitis is not supported by the outcomes of the PACE trial.

It is well documented that one of the main features of chronic fatigue syndrome (CFS) (also known as myalgic encephalomyelitis or ME) is an adverse reaction to activity, whereby symptoms are exacerbated after minimal activity. This unusual (and possibly unique) reaction to activity [1,2], sometimes known as post exertional malaise, is a required symptom for the UK’s National Institute for Health and Care Excellence (NICE) guidelines for a diagnosis of CFS/ME [3]. It is characterised by a delayed but prolonged exacerbation of symptoms that is not relieved by ordinary rest [4,5,6].

CFS/ME patients often describe having flu-like symptoms [4], and many people can relate to the experience of reducing activity (e.g. taking time off work) when severely ill with flu. Reducing activity levels, in response to illness, is a feature of “sickness behaviour” and is a widely recognised adaptive and protective mechanism [7,8]. CFS/ME symptoms are exacerbated with exertion, so patients learn to adapt to their illness rather than persistently exacerbating the symptoms by over exerting themselves [9].

Within the field of psychiatry this behavioural adaptation by CFS/ME patients has been interpreted as a maladaptive response to symptoms of fatigue and pain. It is claimed that maladaptive fear and avoidance of activity, and associated deconditioning, perpetuate the symptoms and that the illness can be reversed with cognitive-behavioural treatments. This is known as the fear-avoidance-deconditioning hypothesis [10,11].

The £5m PACE trial was set up to test the fear-avoidance-deconditioning hypothesis for CFS. It tested cognitive behavioural therapy (CBT) and graded exercise therapy (GET) against a usual care control group (specialist medical care) as treatments for CFS. A novel therapy known as adaptive pacing therapy, created specifically for the PACE trial, was also tested. CBT was designed to reduce fear and avoidance of activity, and GET was designed to reduce avoidance behaviour. Both were intended to reduce deconditioning and to lead to improved symptoms, improved physical function, a reversal of the illness, and ultimately recovery [10,11,12].

For the PACE trial, the cognitive-behavioural interventions were not intended as adjunctive therapies to assist patients to adjust to their health problems, or to address secondary complications or comorbid disorders, but were intended as primary treatments to treat the presumed perpetuating factors and ultimately to reverse the illness itself. Thus, for an illness that is widely considered to be a biomedical illness, with many catalogued immunological and neurological abnormalities [13-22], we are presented with a psychotherapy which is intended to reverse the illness itself.

Despite the hyperbole and misrepresentation in the media reporting, the outcomes of the PACE trial do not support the fear-avoidance-deconditioning hypothesis in CFS/ME.

CBT was designed to reverse the illness, by addressing a hypothetical maladaptive fear-avoidance response to symptoms. If the illness itself had been reversed and successfully treated, then one would expect to see improvements in objectively measured outcomes of disability. But there were no improvements in any of the objective measures (e.g. a six minute walking distance test and a step test) after treatment with CBT in the PACE trial. So it seems clear that CBT failed to reverse the illness, demonstrating that the fear-avoidance hypothesis was not supported by the outcomes of the PACE trial project.

Furthermore, Chalder et al. acknowledge that CBT and GET failed to improve deconditioning (fitness assessed by a step test), and that the deconditioning hypothesis, upon which the PACE trial was based, was not supported by the outcomes: “Fitness measures did not mediate the effects of the treatments.” [23].

So, there was a clear failure to demonstrate the validity of the fear-avoidance-deconditioning hypothesis tested in the PACE trial.

Although it was a large and expensive government-funded trial, the PACE trial, as with most cognitive-behavioural research, was open-label and failed to control for placebo effects and biases such as response bias [24,25]. CBT and GET changed the way that a minority of patients interpreted their illness and responded to self-report questionnaires, as demonstrated by the 11-15% self-report clinical response rate to CBT/GET, but as placebo effects and response bias were not controlled for in this open-label study, it is possible that the self-reported effects could be explained by weaknesses of the trial methodology [24-28].

Because of the potentially severe adverse reaction to exertion experienced by CFS/ME patients, cognitive-behavioural therapies, including exercise therapy, are not necessarily benign interventions. Kindlon reported that harms associated with cognitive-behavioural therapies have not been systematically reported in peer-reviewed CFS/ME research, however, in an analysis of a range of patient surveys Kindlon reported that 51% (n=4338) of CFS/ME patients have reported being harmed after receiving GET, and 21% (n=1808) have reported being harmed after CBT. In contrast, 2.6% (n=5894) reported being harmed by pacing, a symptom management tool popular with patients [29,30]. Deterioration rates were reported for the PACE trial [31], but not as an equivalent measure to the criteria for improvement, so the rigour and relevance of the data is questionable [32].

Members of the patient community, specialist clinicians, researchers, and patient organisations, are bewildered by the cognitive-behavioural hypothesis for the treatment of CFS/ME [33-36], in much the same way as cancer patients might react if they were to be prescribed psychotherapy as a primary treatment intended to reduce and reverse a tumour. Thus we have a situation where we have a conflict between the patient community, who obviously have a great deal of insight into their illness, and those within the field of psychiatry who would impose a model of illness that patients widely consider to be inappropriate and unsupported by rigorous empirical evidence. The results of the PACE trial appear to support the views widely held by the patient community.

Considering the outcomes of PACE trial, it is time for proponents of CBT and GET to reassess their empirically unsupported model of illness. If CFS/ME patients were to be offered non-pharmacological interventions purely as a means of support to help cope with the challenges of living with a profoundly incapacitating chronic illness, then this may reduce conflict.

£5m was spent on the PACE trial, with no clinically useful improvements in objectively measured outcomes, but no government funding was spent on biomedical research into CFS/ME during the same period. Perhaps it is time for the Medical Research Council to focus on funding biomedical research, in this vastly underfunded illness [37].

References:

1. Snell CR, Stevens SR, Davenport TE, Van Ness JM. (2013) Discriminative validity of metabolic and workload measurements for identifying people with chronic fatigue syndrome. Phys Ther. 93:1484-92.

2. White AT, Light AR, Hughen RW, Vanhaitsma TA, Light KC. (2012) Differences in metabolite-detecting, adrenergic, and immune gene expression after moderate exercise in patients with chronic fatigue syndrome, patients with multiple sclerosis, and healthy controls. Psychosom Med. 74:46-54.

3. NICE (2007). Chronic fatigue syndrome / Myalgic encephalomyelitis: full guideline. Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (or Encephalopathy): Diagnosis and Management of CFS/ME in Adults and Children. National Institute for Health and Clinical Excellence (NICE) Clinical Guideline 53. http://guidance.nice.org.uk/CG53/Guidance/pdf/English

4. Carruthers BM, Jain AK, De Meirleir KL, Peterson DL, Klimas NG, Lerner AM, Bested AC, Flor-Henry P, Joshi P, Powles AC, Sherkey JA, van de Sande MI. (2003) Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Clinical Working Case Definition, Diagnostic and Treatment Protocols. Journal of Chronic Fatigue Syndrome 11:7-115.

5. VanNess JM, Stevens SR, Bateman L, Stiles TL, Snell CR. (2010) Postexertional malaise in women with chronic fatigue syndrome. J Womens Health (Larchmt). 19:239-44.

6. Van Oosterwijck J, Nijs J, Meeus M, Lefever I, Huybrechts L, Lambrecht L, Paul L. (2010). Pain inhibition and postexertional malaise in myalgic encephalomyelitis⁄chronic fatigue syndrome: An experimental study. J Intern Med. 268:265-78.

7. Hart BL. (1988) Biological basis of the behavior of sick animals. Neurosci Biobehav Rev. 12:123-37.

8. Kelley KW, Bluthé RM, Dantzer R, Zhou JH, Shen WH, Johnson RW, Broussard SR. (2003) Cytokine-induced sickness behavior. Brain Behav Immun. 17:S112-8.

9. Center for Drug Evaluation and Research (CDER), U.S. Food and Drug Administration (FDA). (2013) The Voice of the Patient. Chronic Fatigue Syndrome and Myalgic Encephalomyelitis. (Internet) (accessed: 20 Jan 2015) http://www.fda.gov/downloads/ForIndustry/UserFees/PrescriptionDrugUserFe...

10. Bavinton J, Darbishire L, White PD. (2004) PACE Manual for Therapists; Graded Exercise Therapy for CFS/ME; Final Trial Version 7. (Internet) (accessed: 16 Jan 2015) http://www.pacetrial.org/docs/get-therapist-manual.pdf

11. Burgess M, Chalder T. (2004) PACE manual for therapists. Cognitive behaviour therapy for CFS/ME. (Internet) (accessed: 17 Jan 2015) http://www.pacetrial.org/docs/cbt-therapist-manual.pdf

12. White PD, Goldsmith KA, Johnson AL et al. (2011) Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial. Lancet 377:823-36.

13. Carruthers BM, van de Sande MI, De Meirleir KL, Klimas NG, Broderick G, Mitchell T, Staines D, Powles ACP, Speight N, Vallings R, Bateman L, Bell DS, Carlo-Stella N, Chia J, Darragh A, Gerken A, Jo D, Lewis D, Light AR, Light K, MarshallGradisnik S, McLaren-Howard J, Mena I, Miwa K, Murovska M, Steven S. (2012) Myalgic Encephalomyelitis - Adult & Paediatric: International consensus primer for medical practitioners. (Internet) (accessed: 21 Jan 2015) http://sacfs.asn.au/download/me_international_consensus_primer_for_medic...

14. Brenu EW, Johnston S, Hardcastle S, Huth TK, Fuller K, Ramos SB, Staines DR, Marshall-Gradisnik SM. (2013) Immune Abnormalities in Patients Meeting New Diagnostic Criteria for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. J Mol Biomark Diagn 4:3.

15. Brenu EW, van Driel ML, Staines DR, Ashton KJ, Hardcastle SL, Keane J, Tajouri L, Peterson D, Ramos SB, Marshall-Gradisnik SM. (2012) Longitudinal investigation of natural killer cells and cytokines in chronic fatigue syndrome/myalgic encephalomyelitis. J Transl Med. 10:88.

16. Curriu M, Carrillo J, Massanella M, Rigau J, Alegre J, Puig J, Garcia-Quintana AM, Castro-Marrero J, Negredo E, Clotet B, Cabrera C, Blanco J. (2013) Screening NK-, B- and T-cell phenotype and function in patients suffering from Chronic Fatigue Syndrome. J Transl Med. 11:68.

17. Fletcher MA, Zeng XR, Maher K, Levis S, Hurwitz B, Antoni M, Broderick G, Klimas NG. (2010) Biomarkers in chronic fatigue syndrome: evaluation of natural killer cell function and dipeptidyl peptidase IV/CD26. PLoS One. 5:e10817.

18. Fluge Ø, Bruland O, Risa K, Storstein A, Kristoffersen EK, Sapkota D, Næss H, Dahl O, Nyland H, Mella O. (2011) Benefit from B-lymphocyte depletion using the anti-CD20 antibody rituximab in chronic fatigue syndrome. A double-blind and placebo-controlled study. PLoS One. 6:e26358.

19. Natelson BH, Weaver SA, Tseng CL, Ottenweller JE. (2005) Spinal fluid abnormalities in patients with chronic fatigue syndrome. Clin Diagn Lab Immunol. 12:52-5.

20. Ojo-Amaize EA, Conley EJ, Peter JB. (1994) Decreased natural killer cell activity is associated with severity of chronic fatigue immune dysfunction syndrome. Clin Infect Dis. Suppl 1:S157-9.

21. Zeineh MM, Kang J, Atlas SW, Raman MM, Reiss AL, Norris JL, Valencia I, Montoya JG. (2014) Right Arcuate Fasciculus Abnormality in Chronic Fatigue Syndrome. Radiology. 29:41079.

22. World Health Organisation ICD-10 G93.3 “Other disorders of brain” http://apps.who.int/classifications/apps/icd/icd10online/?gg90.htm+g933

23. Chalder T, Goldsmith KA, White PD, Sharpe M, Pickles AR. (2015) Rehabilitative therapies for chronic fatigue syndrome: a secondary mediation analysis of the PACE trial. The Lancet Psychiatry (online first).

24. Kindlon TP (2015) Objective measures found a lack of improvement for CBT & GET in the PACE Trial: subjective improvements may simply represent response biases or placebo effects in this non-blinded trial. BMJ Rapid Response. (Internet) (accessed: 21 Jan 2015) http://www.bmj.com/content/350/bmj.h227/rr-10

25. Wilshire CE (2015) Re: Tackling fears about exercise is important for ME treatment, analysis indicates. BMJ Rapid Response. (Internet) (accessed: 21 Jan 2015) http://www.bmj.com/content/350/bmj.h227/rr-7

26. Boot WR, Simons DJ, Stothart C, Stutts C. (2013) The Pervasive Problem With Placebos in Psychology Why Active Control Groups Are Not Sufficient to Rule Out Placebo Effects. Perspect Psychol Sci. 8:445-454.

27. Jauhar S, McKenna PJ, Radua J, Fung E, Salvador R, Laws KR. (2014) Cognitive-behavioural therapy for the symptoms of schizophrenia: systematic review and meta-analysis with examination of potential bias. Br J Psychiatry. 204:20-9.

28. Wechsler ME, Kelley JM, Boyd IO, Dutile S, Marigowda G, Kirsch I, Israel E, Kaptchuk TJ. (2011) Active albuterol or placebo, sham acupuncture, or no intervention in asthma. N Engl J Med. 365:119-26.

29. Kindlon T. (2011) Reporting of harms associated with graded exercise therapy and cognitive behavioural therapy in myalgic encephalomyelitis/chronic fatigue syndrome. Bull IACFS/ME 19:59–111.

30. Goudsmit EM, Nijs J, Jason LA, Wallman KE. (2012) Pacing as a strategy to improve energy management in myalgic encephalomyelitis/chronic fatigue syndrome: a consensus document. Disabil Rehabil. 34:1140-7.

31. Dougall D, Johnson A, Goldsmith K, Sharpe M, Angus B, Chalder T, White P. (2014) Adverse events and deterioration reported by participants in the PACE trial of therapies for chronic fatigue syndrome. J Psychosom Res. 77:20-6.

32. Guyatt GH, Osoba D, Wu AW, Wyrwich KW, Norman GR; Clinical Significance Consensus Meeting Group. (2002) Methods to explain the clinical significance of health status measures.Mayo Clin Proc. 77:371-83.

33. Burch S. (2015) Prof. VanNess on recent press reports. Just ME blog. (Internet) (accessed: 21 Jan 2015) http://sallyjustme.blogspot.co.uk/2015/01/dr-vanness-on-recent-press-rep...

34. ME Research UK. (2015) Fear Avoidance of Exercise? (Internet) (accessed: 21 Jan 2015) http://www.meresearch.org.uk/news/fear-avoidance-of-exercise/

35. Shepherd CB. (2015) Conclusions about graded exercise fail to recognise the complexities of ME/CFS. BMJ Rapid Response. (Internet) (accessed: 21 Jan 2015) http://www.bmj.com/content/350/bmj.h227/rr-6

36. Weir WRC. (2015) Re: Tackling fears about exercise is important for ME treatment, analysis indicates. BMJ Rapid Response. (Internet) (accessed: 21 Jan 2015) http://www.bmj.com/content/350/bmj.h227/rr-13

37. MEAnalysis (2014) ME - Science Friction in the UK. YouTube Video. (Internet) (last accessed: 20 Jan 2015) www.youtube.com/watch?v=j2biXfyV1bY

Competing interests: No competing interests

23 January 2015
Robert Courtney
N/A
London
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