1. Turku PET Centre, University of Turku, Turku, Finland
2. Department of Public Health, University of Helsinki, Helsinki, Finland
3. Institute for Molecular Medicine, Helsinki, Finland
4. Unit for Genetic Epidemiology, National Institute for Health and Welfare, Helsinki, Finland
5. Institute of Clinical Medicine, Family Medicine, University of Turku, Turku, Finland
6. Department of Family Medicine, University Hospital of Turku, Turku, Finland
7. Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland