1. Department of Health Economics and Health Services Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
2. Department of General Practice, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
3. Hannover Medical School, Institute of General Practice, Hannover, Germany
4. Central Institute of Mental Health, Mannheim/Heidelberg University,Mannheim, Germany
5. Department of General Practice, Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany
6. Occupational Medicine and Public Health, Institute of Social Medicine, University of Leipzig, Leipzig, Germany
7. Department of Psychiatry, Technical University of Munich, Munich, Germany
8. Department of Psychiatry, University of Bonn, Bonn, Germany
9. German Center for Neurodegenerative Diseases, Bonn, Germany