1. Department for Clinical Psychology and Psychotherapy, University of Marburg, 35032 Marburg, Germany
2. Department for Pain Management, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil Bochum, Ruhr University Bochum, 44789 Bochum, Germany
3. Department for Psychosomatic Medicine, University of Technology Munich, 80333 München, Germany