1. Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Hannover, Germany.
2. Department of General, Abdominal, and Bariatric Surgery, Herzogin Elisabeth Hospital, Braunschweig, Germany.
3. Department of Psychosomatic Medicine and Psychotherapy, Hannover Medical School, Hannover, Germany.
4. Insitute of Clinical Chemistry, Hannover Medical School, Hannover, Germany.