1. Department of Health & Social Psychology, Institute of Psychology, German Sport University Cologne, 50933 Cologne, Germany
2. Department of Psychosomatics and Psychotherapy, Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
3. Trimberg Research Academy, University of Bamberg, 96045 Bamberg, Germany
4. Department of Psychology and Psychotherapy, Witten/Herdecke University, 58455 Witten, Germany
5. Department of Psychosomatic Medicine, Robert-Bosch-Krankenhaus Stuttgart, 70376 Stuttgart, Germany