[1] Uppsala Univ, Dept Psychol, SE-75142 Uppsala, Sweden
[2] Aarhus Univ, Danish Epidemiol Sci Ctr, DK-8000 Aarhus C, Denmark
[3] Univ Calif Los Angeles, Dept Epidemiol, Los Angeles, CA 90024 USA
[4] Univ Oulu, Clin Child Psychiat, Oulu, Finland
[5] Univ Hosp Oulu, Oulu, Finland
[6] Univ Oulu, Inst Hlth Sci, Oulu, Finland
[7] Aarhus Univ Hosp, Dept Pediat, Skejby, Denmark
[8] Dept Obstet, Perinatal Epidemiol Res Unit, Aarhus, Denmark
[9] Univ Oulu, Dept Psychiat, Oulu, Finland
[10] Aarhus Univ, Inst Publ Hlth, Dept Gen Practice, DK-8000 Aarhus C, Denmark
[11] Univ London Imperial Coll Sci Technol & Med, Dept Epidemiol & Publ Hlth, London SW7 2AZ, England
[12] Univ Oulu, Bioctr Oulu, Oulu, Finland
[13] Kings Coll London, Inst Psychiat, MRC Social Genet Dev Psychiat Ctr, London WC2R 2LS, England