[1] Univ London Imperial Coll Sci Technol & Med, Dept Med, Ctr Mental Hlth, London, England
[2] Univ Barcelona, St Joan de Deu Hosp, Dept Child & Adolescent Psychiat & Psychol, Barcelona, Spain
[3] Imperial Coll Healthcare NHS Trust, St Marys Hosp, Dept Paediat Intens Care, London, England
[4] Great Ormond St Hosp Sick Children, Great Ormond St Hosp, Dept Paediat Intens Care, London WC1N 3JH, England