[1] Univ Zurich, Dept Child & Adolescent Psychiat, CH-8032 Zurich, Switzerland
[2] Buskerud Hosp, Dept Child & Adolescent Psychiat, Drammen, Norway
[3] Univ Reykjavik, Dept Child & Adolescent Psychiat, Reykjavik, Iceland
[4] Univ Roma Tor Vergata, Dept Child Neuropsychiat, Rome, Italy
[5] Eli Lilly & Co, Lilly Res Ctr, Windlesham, Surrey, England
[6] Med Ctr Rijnmond S, Dept Pediat, Rotterdam, Netherlands