1. King’s Centre for Military Health Research, Department of Psychological Medicine, Institute for Psychiatry, Psychology & Neuroscience, King’s College London , London , UK
2. Department of Psychological Medicine, Institute for Psychiatry, Psychology & Neuroscience, King’s College London , London , UK
3. Exeter University Medical School, University of Exeter , Exeter , UK
4. Division of Psychology, Department of Life Sciences, Brunel University London , London , UK
5. Department of Old Age Psychiatry, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London , London , UK
6. Department of Medicine, Imperial College London , London , UK