Cognitive behaviour therapy (CBT)
CBT was done on the basis of the fear avoidance theory of
chronic fatigue syndrome. This theory regards chronic fatigue
syndrome as being reversible and that cognitive responses
(fear of engaging in activity) and behavioural responses
(avoidance of activity) are linked and interact with
physiological processes to perpetuate fatigue. The aim of
treatment was to change the behavioural and cognitive
factors assumed to be responsible for perpetuation of the
participant’s symptoms and disability. Therapeutic strategies
guided participants to address unhelpful cognitions,
including fears about symptoms or activity by testing them in
behavioural experiments. These experiments consisted of
establishing a baseline of activity and rest and a regular sleep
pattern, and then making collaboratively planned gradual
increases in both physical and mental activity. Furthermore,
participants were helped to address social and emotional
obstacles to improvement through problem-solving. Therapy
manuals were based on manuals used in previous trials.19–21
CBT was delivered mainly by clinical psychologists and nurse
therapists (webappendix p 1).
Graded exercise therapy (GET)
GET was done on the basis of deconditioning and exercise
intolerance theories of chronic fatigue syndrome. These
theories assume that the syndrome is perpetuated by
reversible physiological changes of deconditioning and
avoidance of activity. These changes result in the
deconditioning being maintained and an increased
perception of eff ort, leading to further inactivity. The aim of
treatment was to help the participant gradually return to
appropriate physical activities, reverse the deconditioning,
and thereby reduce fatigue and disability. Therapeutic
strategies consisted of establishment of a baseline of
achievable exercise or physical activity, followed by a
negotiated, incremental increase in the duration of time
spent physically active. Target heart rate ranges were set
when necessary to avoid overexertion, which eventually
aimed at 30 min of light exercise fi ve times a week. When this
rate was achieved, the intensity and aerobic nature of the
exercise was gradually increased, with participant feedback
and mutual planning. The most commonly chosen exercise
was walking. The therapy manual was based on that used in
previous trials.22,23 GET was delivered by physiotherapists and
one exercise physiologist (webappendix p 1).
