In their study Kennedy and colleagues demonstrate that in patients
with irritable bowel syndrome a six week course of cognitive behaviour
therapy (CBT) shows a significant benefit on symptom severity in
comparison with ‘no treatment’. Figure 2 in their article suggests that
the relative benefit of CBT reaches a maximum shortly after the
intervention has ended at 3 months. The effect of CBT however wears off,
leaving no significant benefit in comparison with ‘no treatment’ during
follow-up at 6 and 12 months.
Both the ‘wearing off’ and the fact that no control for CBT was
included makes me wonder if not all I am looking at is a placebo-effect. I
would suggest the study to be repeated with a control group receiving re-
assurance in combination with some kind of psychological intervention with
the same frequency and duration as the CBT that is given.
At this moment I believe your report that ‘cognitive behaviour
therapy reduces symptom severity of irritable bowel syndrome’ in a
headline of ‘This week in the BMJ’ is premature, as is the suggestion that
‘cognitive behaviour therapy seems a useful addition to drugs treatment’
in ‘What this study adds’.
Bart van Pinxteren
Competing interests: No competing interests