1. Department of Palliative Medicine; University Hospital of Bonn; Bonn Germany
2. Center for Rare Diseases Bonn (ZSEB); University Hospital of Bonn; Bonn Germany
3. Department of General Practice and Family Medicine; University Hospital of Bonn; Bonn Germany
4. National Drug and Alcohol Research Centre; University of New South Wales; Sydney Australia
5. Centre for Youth Substance Abuse Research; The University of Queensland; Brisbane Australia
6. Centre for Palliative Care; Malteser Hospital Bonn/Rhein-Sieg; Bonn Germany
7. Department of Psychosomatic Medicine and Psychotherapy; Technische Universität München; Munich Germany
8. Department of Psychosomatic Medicine and Psychotherapy; University Hospital of Bonn; Bonn Germany