[1] Univ Liverpool, Dept Psychiat, Inst Human Ageing, Liverpool L69 3GA, Merseyside, England
[2] Vrije Univ Amsterdam, Dept Psychiat, Amsterdam, Netherlands
[3] St James Hosp, Dept Psychiat Elderly, Dublin 8, Ireland
[4] Hosp Clin Univ, Dept Psychiat, Zaragoza, Spain
[5] Inst Psychiat, Sect Epidemiol & Gen Practice & Old Age Psychiat, London, England
[6] Univ Munich, Dept Psychiat, D-8000 Munich, Germany
[7] London Sch Hyg & Trop Med, Epidemiol Unit, London WC1, England
[8] Free Univ Berlin Klinikum, Dept Psychiat, Berlin, Germany
[9] Osped Civile, Clin Psichiatr, Brescia, Italy
[10] Univ Maastricht, Dept Psychiat, Maastricht, Netherlands