1. Demography Unit, Department of Sociology, Stockholm University, S-106 91 Stockholm, Sweden
2. Swedish Institute for Social Research, Stockholm University, S-106 91 Stockholm, Sweden
3. Department of Science, Bahçeşehir University, Istanbul, Turkey
4. Department of Psychiatry, Institute of Clinical Medicine, University of Oulu, Oulu, Finland
5. Oulu University Hospital, Oulu, Finland
6. Institute of Health Sciences, University of Oulu, Oulu, Finland
7. Unit of General Practice, Oulu University Hospital, Oulu, Finland