[1] Kings Coll London, Inst Psychiat, Psychosis Studies, London, England
[2] Kings Coll London, Inst Psychiat, Hlth Serv & Populat Res, London, England
[3] Univ Palermo, Dipartimento Biomed Sperimentale & Neurosci Clin, Palermo, Italy
[4] Kings Coll London, Inst Psychiat, MRC Social Genet & Dev Psychiat Ctr, London, England