1 Department of Health Services Research and Policy, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK; Department of Health Services and Population Research, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK.
2 Department of Health Services Research and Policy, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK; Department of Health Services and Population Research, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK; The MHPSS Collaborative, hosted by Save the Children, Copenhagen, Denmark.
3 Centre for Longitudinal Studies and MRC Unit for Lifelong Health and Ageing, Social Research Institute and Faculty of Population Health Science, University College London, London WC1E 6DH, UK. Electronic address: p.patalay@ucl.ac.uk.