Therapist effects and the dissemination of cognitive behavior therapy for chronic fatigue syndrome in community-based mental health care.

Objective: The purpose of the present study was to explore the role of the therapist in the dissemination of manualized cognitive behavior therapy (CBT) for chronic fatigue syndrome (CFS) outside specialized treatment settings.

Method: We used the routinely collected outcome data of three community-based mental health care centers (MHCs) which implemented and sustained CBT for CFS during the course of the study. Ten therapists, who all received the same training in CBT for CFS, and 103 patients with CFS were included.

Results: Random effects modeling revealed a significant difference in mean post-treatment fatigue between therapists. The effect of the therapist accounted for 21% of the total variance in post-treatment fatigue in our sample. This effect could be explained by the therapists' attitude toward working with evidence-based treatment manuals as well as by the MHC where CBT for CFS was delivered.

Conclusion: The context in which CBT for CFS is delivered may play an important role in the accomplishment of established therapy effects outside specialized treatment settings. Due to the small sample size of MHCs and the different implementation scenarios in which they were engaged, our findings should be interpreted as preliminary results which are in need for replication.