[1] Kings Coll London, London Inst Psychiat, London WC2R 2LS, England
[2] Univ Pittsburgh, Sch Dent Med, Dept Dent Publ Hlth, Pittsburgh, PA USA
[3] NIA, Lab Epidemiol Demog & Biometry, Bethesda, MD 20892 USA
[4] Univ Tennessee, Dept Prevent Med, Knoxville, TN USA
[5] NIA, Clin Res Branch, Baltimore, MD 21224 USA
[6] Univ Calif San Francisco, Dept Psychiat, San Francisco, CA USA
[7] Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA
[8] Univ Calif San Francisco, Dept Epidemiol, San Francisco, CA 94143 USA
[9] Univ Pittsburgh, Grad Sch Publ Hlth, Ctr Aging & Populat Hlth, Pittsburgh, PA USA