In their recent paper [1], Lakhan & Schofield state that: "However, the limitations of CBT noted above apply equally to somatization disorders - for example, only 30% of patients with CFS experience full recovery following conventional CBT." Without going into whether CFS is a "somatization disorder" per se, the cited paper for this statement (White et al, 2011) [2] did not report on a full recovery, which was made clear in a subsequent authors' reply. [3]

White et al had instead reported on the proportion of participants within 'normal range' at followup, defined as ≤ 18/33 points in fatigue score (CFQ, Likert scoring) and ≥ 60/100 points in physical function (SF-36 health survey). The proportion of participants meeting this threshold at followup was 15% for SMC (specialist medical care) and 30% for SMC+CBT, which translates to a Number Needed to Treat of about 7.

A similarly inaccurate comment about full recovery was made in the Lancet editorial [4] which accompanied the CFS study in question [2], which the Press Complaints Commission in the UK later ruled was misleading and raising a breach of Clause 1 (Accuracy) of the Code, because the authors of the editorial failed make it clear that their comment reflected their personal view rather than the paper being commented on.[5]

However, it should also be noted that even the authors of the Lancet editorial in question (Knoop & Bleijenberg) have previously co-authored papers on CFS in which 60-65/100 points in physical function was not only regarded as non-recovered [6], but even reflective of "severe" problems with physical functioning.[7][8][9]

Upon closer inspection, it becomes more obvious that the thresholds used do not indicate a full recovery. It was theoretically possible for a participant to be within 'normal range' at baseline, despite the same scores meeting trial eligibility criteria for "disabling fatigue". In practice, almost no participants reported normal fatigue at baseline, but 13% of participants had reported normal physical function at baseline, despite the same scores counting as "significant disability".[10][2]

These low thresholds were seemingly derived from the questionable use of normative population data.[11][12]

References:

1. Lakhan SE, Schofield KL (2013) Mindfulness-Based Therapies in the Treatment of Somatization Disorders: A Systematic Review and Meta-Analysis. PLoS ONE 8(8): e71834. doi:10.1371/journal.pone.0071834
http://www.plosone.org/ar...

2. White PD, Goldsmith KA, Johnson AL, Potts L, Walwyn R, 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: 823–836. doi: 10.1016/s0140-6736(11)60096-2. http://www.ncbi.nlm.nih.g...

3. White PD, Goldsmith KA, Johnson AL, Walwyn R, Baber HL, Chalder T, Sharpe M, [on behalf of the coauthors]. The PACE trial in chronic fatigue syndrome — Authors' reply. The Lancet, Volume 377, Issue 9780, Pages 1834 - 1835, 28 May 2011 (Published Online: 17 May 2011). doi:10.1016/S0140-6736(11)60651-X http://www.thelancet.com/...

4. Bleijenberg G, Knoop H. Chronic fatigue syndrome: where to PACE from here? Lancet. 2011 Mar 5;377(9768):786-8. Epub 2011 Feb 18. DOI: 10.1016/S0140-6736(11)60172-4 http://www.ncbi.nlm.nih.g...

5. http://www.pcc.org.uk/new...

6. Knoop H, Bleijenberg G, Gielissen MFM, van der Meer JWM, White PD. Is a full recovery possible after cognitive behavioural therapy for chronic fatigue syndrome? Psychother Psychosom 2007; 76: 171–76. PMID 17426416.

7. van't Leven M, Zielhuis GA, van der Meer JW, Verbeek AL, Bleijenberg G. Fatigue and chronic fatigue syndrome-like complaints in the general population. Eur J Public Health. 2010 Jun;20(3):251-7. Epub 2009 Aug 18. PMID 19689970 http://eurpub.oxfordjourn...

8. Heins M, Knoop H, Nijs J, Feskens R, Meeus M, Moorkens G, Bleijenberg G. Influence of symptom expectancies on stair-climbing performance in chronic fatigue syndrome: effect of study context. Int J Behav Med. 2013 Jun;20(2):213-8. doi: 10.1007/s12529-012-9253-2. http://www.ncbi.nlm.nih.g...

9. Tummers M, Knoop H, van Dam A, Bleijenberg G. Implementing a minimal intervention for chronic fatigue syndrome in a mental health centre: a randomized controlled trial. Psychol Med. 2012 Oct;42(10):2205-15. doi: 10.1017/S0033291712000232. Epub 2012 Feb 21. http://www.ncbi.nlm.nih.g...

10. Queen Mary, University of London. FOI Request: 2013/F42. https://listserv.nodak.ed...

11. Feehan SM; Liverpool ME Support Group. The PACE trial in chronic fatigue syndrome. Lancet. 2011 May 28;377(9780):1831-2. Epub 2011 May 16. doi: 10.1016/S0140-6736(11)60688-0 http://www.ncbi.nlm.nih.g...

12. Kewley AJ. The PACE trial in chronic fatigue syndrome. Lancet. 2011 May 28;377(9780):1832. Epub 2011 May 16. doi:10.1016/S0140-6736(11)60681-8 http://www.ncbi.nlm.nih.g...