1. Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil gGmbHRuhr-University BochumDepartment of Gastroenterology and HepatologyGermany
2. Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil gGmbHRuhr-University BochumDepartment of Pain MedicineGermany
3. KRH Klinikum Agnes Karll LaatzenDepartment of Internal Medicine and GastroenterologyLaatzenGermany
4. LVR-Hospital EssenDepartment of Psychiatry and PsychotherapyFaculty of MedicineUniversity of Duisburg-EssenEssenGermany
5. University of MünsterDepartment of PsychologyMünsterGermany