1. Department of Public Health; University of Helsinki; Finland
2. Departments of Psychiatry and Nutrition; University of North Carolina at Chapel Hill; Chapel Hill North Carolina
3. Department of Adolescent Psychiatry; Helsinki University Central Hospital; Helsinki Finland
4. Institute of Clinical Medicine, Child Psychiatry, University of Turku; Finland
5. National Institute for Health and Welfare; Helsinki Finland
6. Department of Medical Epidemiology and Biostatistics; Karolinska Institutet; Stockholm Sweden
7. Department of Psychiatry; Helsinki University Central Hospital; Finland
8. Parnassia Psychiatric Institute; The Hague The Netherlands
9. Department of Psychiatry; Groningen University; The Netherlands
10. Department of Epidemiology; Columbia University; New York
11. Institute for Molecular Medicine Finland FIMM, University of Helsinki; Finland