Does a decrease in avoidance behavior and focusing on fatigue mediate the effect of cognitive behavior therapy for chronic fatigue syndrome?

OBJECTIVE Cognitive behavior therapy (CBT) leads to a significant reduction in fatigue severity and impairment in patients with chronic fatigue syndrome (CFS). The purpose of the present study was to determine whether the effect of CBT for CFS on fatigue and impairment is mediated by a decrease in avoidance behavior and focusing on fatigue. METHODS For this purpose, we reanalyzed a randomized controlled trial which was previously conducted to test the efficacy of CBT for CFS. Two hundred nineteen patients completed assessment prior and subsequent to treatment or a control group period. RESULTS Mediation analysis revealed that a decrease in focusing on fatigue mediated the effect of CBT for CFS on fatigue and impairment. Avoidance of activity and avoidance of aversive stimuli were not significantly changed by treatment and were therefore excluded from mediation analysis. CONCLUSION A decrease in the focus on fatigue seems to contribute to the treatment effect of CBT for CFS.