1. University College London; Mental Health Sciences; Charles Bell House 57-73 Riding House Street London UK WiW 7EJ
2. Guy's, King's & St Thomas School of Medicine & Institute of Psychiatry; Academic Dept of Psychological Medicine; 103 Denmark Hill London UK SE5 8AF
3. MRC National Survey of Health and Development; Department of Epidemiology and Public Health; 33 Bedford Place London UK WC1B 5JU