[1] Erasmus MC, Univ Med Ctr, Dept Child & Adolescent Psychiat Psychol, Rotterdam, Netherlands
[2] Erasmus Univ, Dept Psychol Educ & Child Studies, Rotterdam, Netherlands
[3] Univ Leeds, Sch Psychol, Leeds, England
[4] UCL, Inst Epidemiol & Hlth Care, Res Dept Behav Sci & Hlth, London, England
[5] Ulster Univ, Inst Nursing & Hlth Res, Belfast, North Ireland
[6] UCL, Dept Behav Sci & Hlth, Gower St, London WC1E 6BT, England