Cognitive behaviour therapy for chronic fatigue syndrome: a multicentre randomised controlled trial

Summary

Background

Cognitive behaviour therapy (CBT) seems a promising treatment for chronic fatigue syndrome (CFS), but the applicability of this treatment outside specialized settings has been questioned. We compared CBT with guided support groups and the natural course in a randomised trial at three centres.

Methods

Of 476 patients diagnosed with CFS, 278 were eligible and willing to take part. 93 were randomly assigned CBT (administered by 13 therapists recently trained in this technique for CFS), 94 were assigned the support-group approach, and 91 the control natural course. Multidimensional assessments were done at baseline, 8 months, and 14 months. The primary outcome variables were fatigue severity (on the checklist individual strength) and functional impairment (on the sickness impact profile) at 8 and 14 months. Data were analysed by intention to treat.

Findings

241 patients had complete data (83 CBT, 80 support groups, 78 natural course) at 8 months. At 14 months CBT was significantly more effective than both control conditions for fatigue severity (CBT vs support groups 5·8 [2·2–9·4]; CBT vs natural course 5·6 [2·1–9·0]) and for functional impairment (CBT vs support groups 263 [38–488]; CBT vs natural course 222 [3–441]). Support groups were not more effective for CFS patients than the natural course. Among the CBT group, clinically significant improvement was seen in fatigue severity for 20 of 58 (35%), in Karnofsky performance status for 28 of 57 (49%), and self-rated improvement for 29 of 58 (50%). Prognostic factors for outcome after CBT were a higher sense of control predicting more improvement, and a passive activity pattern and focusing on bodily symptoms predicting less improvement.

Interpretation

CBT was more effective than guided support groups and the natural course in a multicentre trial with many therapists. Our study showed a lower proportion of patients with improvement than CBT trials with a few highly skilled therapists.

Introduction

Chronic fatigue syndrome (CFS) is characterised by persistent or relapsing unexplained fatigue, of new or definite onset and lasting for at least 6 months. Fatigue is not the result of an organic disease or ongoing exertion, rest does not alleviate it, and there is substantial limitation of occupational, educational, social, and personal activities.¹ No cause of CFS has been found, and most patients do not recover. No somatic or pharmacological treatments have proven to be effective.² Cognitive behaviour therapy (CBT) seems to be a promising treatment of CFS.3, 4, 5 Two randomised controlled trials reported positive results.6, 7 A recent review² questioned whether these results can be generalised outside specialist centres where only a few highly skilled therapists, or even a single therapist,⁷ administered CBT. Furthermore, in both studies the primary outcome variable was functional impairment and not fatigue, the main complaint of CFS patients.

In our study, criticisms of both previous randomized trials were addressed. The effectiveness of CBT was tested in a multicentre randomised trial. CBT was compared with a treatment condition, guided support groups, and a control condition, the natural course. CBT was administered in three different centres rather than one specialist centre. Experts taught the treatment protocol to many therapists with no previous experience in CBT for CFS. Guided support groups should control for the absence of specific cognitive-behavioural interventions and the presence of therapist's attention and treatment expectations. We assumed that support groups, as in other chronic diseases,8, 9 might contribute to a feeling of mutual understanding, acceptance, and support, and thereby have a healing effect.

In this study, the outcome variables were fatigue severity and functional impairment, with the same instruments used for inclusion and outcome. Moreover, CBT for CFS was based on a statistically tested model of perpetuating factors in CFS10, 11 rather than on hypothesised factors in CFS or on treatments of other medically unexplained syndromes. The model of CFS is shown in figure 1. Focusing on bodily symptoms, low physical activity, and low sense of control contribute to increasing severity of fatigue and functional impairment. CBT is directed at these perpetuating factors. The main aim of our multicentre trial was to show the effectiveness of CBT for patients with CFS. Our hypothesis was that fatigue severity and functional impairment should decrease significantly more in the group of patients assigned CBT than in patients in the control groups.