1. Department of Psychiatry, University of Turku, Turku, Finland.
2. Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
3. Department of Psychiatry, Turku University Hospital, Turku, Finland.
4. Research Department of the Social Insurance Institution of Finland, Turku, Finland.
5. National Institute for Health and Welfare, Turku, Finland.
6. Department of Psychology, Åbo Akademi University, Turku, Finland.
7. Department of Psychiatry, University of Helsinki, Helsinki, Finland.