According to trial data reported in the journal The Lancet Psychiatry, one of the most important elements of improving physical function in patients with chronic fatigue syndrome is using therapy to reduce fear that exercise will worsen rather than improve symptoms.
Sometimes known as "myalgic encephalomyelitis," or "ME," chronic fatigue syndrome (CFS) is defined by symptoms of severe exhaustion that affect patients' everyday lives and their abilities to perform routine tasks.
In 2011, The Lancet published results from the PACE trial, which investigated the following treatments for CFS:
- Cognitive behavior therapy (CBT) - a talking therapy that involves a health professional helping the patient to understand their symptoms and change how they think about and respond to them
- Graded exercise therapy (GET) - a personalized exercise program conducted by a physiotherapist who gradually increases the patient's level of exercise across the program
- Adaptive pacing therapy (APT) - a therapy where patients alter their activity levels to make the best use of their available energy.
The researchers behind the new study - from King's College London, Oxford University and Queen Mary University of London, all in the UK - re-examined the PACE data using a statistical method called meditation analysis.
The researchers were interested in identifying the beliefs about exercise and physical fitness that are used in CBT and GET to improve fatigue symptoms and physical function in CFS patients.
CFS interventions have only 'moderate' benefit
The team found that, although CBT and GET were safe and effective for the majority of patients with CFS, the improvements in the PACE trial were only moderate. The authors explain that by identifying the mechanisms by which some patients benefit from treatment, their research will help to optimize these treatments.
Analyzing a variety of mediating factors, the authors report that the most influential factor on the success of CBT and GET for CFS patients is to reduce "fear avoidance beliefs." These beliefs are fears from patients - considered to be "understandable" by the authors - that their symptoms will be made worse by activity or exercise.
Fear avoidance beliefs were calculated by the authors to account for up to 60% of the overall effect of CBT or GET on patient outcomes.
GET was found to be more successful than CBT at improving fear avoidance and improving exercise tolerance, which was measured by the number of meters walked by patients during a fixed time period.
Prof. Trudie Chalder, from King's College London, says:
"Our results suggest that fearful beliefs can be changed by directly challenging such beliefs (as in CBT) or by simple behavior change with a graded approach to the avoided activity (as in GET). Clinically, the results suggest that therapists delivering CBT could encourage more physical activities, such as walking, which might enhance the effect of CBT and could be more acceptable to patients."
Writing in a linked comment, Dr. Hans Knoop and Jan Wiborg, from Radboud University Medical Centre in the Netherlands, draw a slightly different conclusion to the study authors.
"Chalder and colleagues conclude that future studies should focus on improving self-efficacy and increasing physical activity because these identified mediators had strong relations with the outcomes," the pair write.
However, Dr. Knoop and Wiborg believe instead "that an increase in physical activity is nothing more than a catalyst for the change in cognitions about activity and symptoms in patients with chronic fatigue syndrome."
The Dutch researchers suggest that future studies should focus on how these beliefs can more rapidly and effectively be changed. Once a patient is convinced that it is possible to increase ability, they argue, an important step toward recovery has been taken - regardless of the actual level of activity involved.