1. Institute for Health and Care Improvement, York St John University, York YO31 7EX, UK
2. School of Medicine, University of Leeds, Leeds LS2 9JT, UK
3. School of Health and Related Research, University of Sheffield, Sheffield S1 4DA, UK
4. Advanced Wellbeing Research Centre, Sheffield Hallam University, Sheffield S9 3TU, UK
5. Department of Health Sciences, University of York, York YO10 5DD, UK
6. School of Psychology, Mediterranean College, 104 34 Athens, Greece
7. Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London WC2R 2LS, UK