The effect of sex, APOE 4 genotype and its interaction on cognition and Lead Investigator: Jie Zhang Institution : E-Mail : drzhangj@yahoo.com Proposal ID : 854 Proposal Description: We intend to examine the effect of sex, APOE genotype and its interaction on neuroimaging, NPI-Q and GDS in the oldest old (including CN, aMCI and AD). We will be focusing on these variables, including comprehensive demographics, cognition, MRI calculated volumes, subject health history, weight and height, NPI-Q, GDS and APOE genotype.