1. Tavistock Research Unit, Tavistock and Portman NHS Foundation Trust, London, UK
2. Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
3. Department of Clinical, Educational and Health Psychology, University College London, London, UK
4. Division of Population Health, University of Manchester, Manchester, UK
5. Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK