[1] Kings Coll London, Sect Perinatal Psychiat, James Black Ctr, Inst Psychiat,Dept Psychol Med, London SE5 9NU, England
[2] Kings Coll London, Inst Psychiat, Dept Psychosis Studies, London SE5 9NU, England
[3] Kings Coll London, Inst Psychiat, MRC Social Genet & Dev Psychiat Ctr, London SE5 9NU, England
[4] Kings Coll London, Inst Psychiat, Dept Hlth Serv & Populat Res, London SE5 9NU, England
[5] Univ Westminster, Dept Psychol, London W1R 8AL, England
[6] Univ Cambridge, Dept Psychiat, Cambridge CB2 1TN, England