1. Department of Psychiatry, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A 9, 48149 Münster, Germany, 2Department of Clinical Radiology, University of Münster, Albert-Schweitzer-Strasse 33, 48149 Münster, Germany, 3Department of Psychosomatic Medicine, University of Leipzig, Semmelweisstrasse 10, 04103 Leipzig, Germany and 4Department of Psychology, University of Mainz, Binger Strasse 14-16, 55122 Mainz, Germany