Number of words: 4560
Number of tables: 3Running head: CBT and chronic fatigue syndrome Key Words: chronic fatigue syndrome, cognitive behaviour therapy, acceptance, healthrelated quality of life, neuroticism.
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AbstractObjective. Increasing the quality of life (QoL) of patients with chronic fatigue is challenging because recovery is seldom achieved. Therefore, it is important to identify processes that improve QoL. This study examined the extent of improvement related to cognitive behaviour group therapy (CBT), and whether improvement is affected by initial levels of acceptance and neuroticism.Methods. Eighty CFS patients followed CBT, and self-reported (pre-post design) on mental and physical QoL (MQoL and PQoL), fatigue, acceptance, neuroticism. The extent of improvement was analyzed using t-tests, effect sizes, and clinically significant change criteria.Whether acceptance and neuroticism at baseline predicted changes, was analyzed by means of correlation and regression analyses.
Results. Significant improvement was found for all variables. The effect size for MQoL andPQoL was small; for acceptance and fatigue moderate. About 20% (MQoL) to 40% (fatigue) of the participants clinically improved.Pre-treatment level of acceptance was negatively correlated with changes in MQoL, not with PQoL changes. Neuroticism pre-treatment was positively related with MQoL changes.Regression analysis showed an effect of acceptance on changes in MQoL beyond the effect of neuroticism.
Conclusions:Although CBT is an evidence-based treatment, the sizes of the effects are often small regarding QoL. Our study also revealed small effect sizes. Our study showed that patient characteristics at baseline were significantly associated with MQoL outcome; indicating that CFS patients with high neuroticism or with a low acceptance show more improvement in MQoL. We propose to specifically target acceptance and neuroticism before treatment in order to maximize clinical relevance.3