1. Division of Clinical Neurosciences; University of Turku and Turku University Hospital; Finland
2. Turku PET Centre; University of Turku and Turku University Hospital; Finland
3. Department of Biostatistics; University of Turku; Finland
4. Nordic School of Public Health; Gothenburg Sweden
5. Folkhälsan Research Center, Biomedicum; University of Helsinki; Finland
6. Department of Public Health; University of Turku; Finland