[1] Univ Torino, Dept Publ Hlth & Pediat, I-10126 Turin, Italy
[2] Univ Med Ctr Hamburg Eppendorf, Dept Child & Adolescent Psychiat Psychotherapy &, Res Unit Child Publ Hlth, Hamburg, Germany
[3] Univ Hertfordshire, CRIPACC, Adolescent & Child Hlth Res, Hatfield AL10 9AB, Herts, England
[4] Inst Mother & Child Hlth, Warsaw, Poland
[5] Univ Jyvaskyla, Dept Hlth Sci, Jyvaskyla, Finland
[6] RigaStradins Univ, Dept Publ Hlth & Epidemiol, Riga, Latvia
[7] Univ Lisbon, P-1699 Lisbon, Portugal
[8] CMDT, Inst Hyg & Trop Med, Lisbon, Portugal