1. Loughborough University; Department of Human Sciences; Loughborough Leicestershire UK LE11 3TU
2. University of California, San Francisco; Psychiatry, Neurology and Epidemiology; 4150 Clement Street San Francisco California USA 94121
3. University College London Department of Epidemiology & Public Health; 1-19 Torrington Place London UK WC1E 6BT
4. University of Cambridge; Department of Psychiatry; Box 189 Addenbrooke's Hospital Cambridge UK CB2 2QO