1. Department of General Psychiatry; University Hospital Heidelberg; Germany
2. Department of General Internal and Psychosomatic Medicine; University Hospital Heidelberg; Germany
3. Department for Addictive Disorders; Psychiatric Centre Nordbaden; Germany
4. Department of Psychosomatic Medicine and Psychotherapy LWL-University Hospital; Ruhr-University Bochum; Germany
5. Centre for Addictive Disorders; Central Institute of Mental Health; Germany
6. Department of Clinical Psychology and Psychotherapy; Otto-Friedrich-University of Bamberg; Germany