Sophie D Bennett1, Isobel Heyman1,2, Anna E Coughtrey1,2, Marta Buszewicz3, Sarah Byford4, Caroline J Dore5, Peter Fonagy6, Tamsin Ford7, Rona Moss-Morris8, Terence Stephenson1, Sophia Varadkar1,2, Erin Walker9, Roz Shafran1. 1. UCL Great Ormond Street Institute of Child Health, London, UK. 2. Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK. 3. Research Department of Primary Care and Population Health, University College London, London, UK. 4. Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK. 5. Comprehensive Clinical Trials Unit, University College London, London, UK. 6. Research Department of Clinical, Educational and Health Psychology, University College London, London, UK. 7. University of Exeter Medical School, University of Exeter, Exeter, UK. 8. Department of Psychology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK. 9. Patient Insight and Involvement, UCLPartners, London, UK.