1. Head of the Department of Psychiatry, Psychotherapy and Psychosomatic Medicine, Evangelisches Krankenhaus Castrop-Rauxel, Academic Teaching Hospital of the University of Duisburg/Essen and Professor, University of Duisburg/Essen, Castrop-Rauxel, Germany
2. Head of the Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke University and Professor, Otto-von-Guericke University, Magdeburg, Germany
3. Senior psychologist in the Department of Psychiatry and Psychotherapy, Faculty of Medicine, LVR-Hospital Essen, University of Duisburg-Essen and Doctor rerum medicarum of the University of Duisburg/Essen, Essen, Germany
4. Head of the Department of Psychiatry and Psychotherapy, Faculty of Medicine, LVR-Hospital Essen, University of Duisburg-Essen and Professor, University of Duisburg/Essen, Essen, Germany