1. Department of Pediatrics, Kangwon National University School of Medicine, Chuncheon, Korea.
2. Department of Pediatrics, Korea University Guro Hospital, Seoul, Korea.
3. Department of Pediatrics, Yeouido St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
4. Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
5. Department of Psychiatry, Hanyang University Medical Center, Seoul, Korea.
6. Department of Psychiatry and Behavioural Science, Seoul National University College of Medicine, Seoul, Korea.