[1] Rush Med Coll, Dept Neurol Sci, Chicago, IL 60612 USA
[2] Univ Helsinki, Dept Neurol, Memory Res Unit, FIN-00014 Helsinki, Finland
[3] Erasmus Univ, Sch Med, Dept Epidemiol & Biostat, NL-3000 DR Rotterdam, Netherlands
[4] Mayo Clin & Mayo Fdn, Dept Hlth Sci Res, Rochester, MN 55905 USA
[5] Mayo Clin & Mayo Fdn, Dept Neurol, Rochester, MN 55905 USA
[6] Sahlgrenska Hosp, Dept Psychiat, Gothenburg, Sweden
[7] Karolinska Inst, Dept Geriatr Med, S-10401 Stockholm, Sweden
[8] Stockholm Gerontol Res Ctr, Stockholm, Sweden