Possible Detrimental Effects of Cognitive Behaviour Therapy for Chronic Fatigue Syndrome

Background: Cognitive behaviour therapy (CBT) for chronic fatigue syndrome (CFS) can decrease the level offatigue and disabilities, but it has been suggested that during therapy some patients experience a deterioration of their symptoms rather than an improvement. The aim of this study is to examine the frequency and severity of symptom deterioration during CBT for CFS. Methods: Data from 3 randomised controlled trials on CBT for CFS were pooled and reanalysed. Symptom deterioration during the trial was rated by patients and measured as deterioration in fatigue, pain, functional impairment and psychological distress. Both the frequency and severity of deterioration in these domains were compared between the patients receiving CBT and those in the control group. Predictors of symptom deterioration were identified by comparing their means in patients with and without an increase in fatigue. Statistically significant predictors were then combined in a logistic regression model. Results: The frequency of symptom deterioration varied from 2 to 12% in patients receiving CBT and from 7 to 17% in the control group. None of the measures showed a significantly higher frequency of symptom deterioration in the CBT group. The severity of deterioration was also comparable in the CBT and in the control group. No predictors of symptom deterioration specific to CBT were found. Conclusion: Patients receiving CBT do not experience more frequent or more severe symptom deterioration than untreated patients. The reported deterioration during CBT seems to reflect the natural variation in symptoms. Thus, CBT is not only a helpful, but also a safe treatment for CFS.