APOE and Mental deterioration: Furthermore, even though the cohort is enriched for APOE-ε4 genotype (38% in this subset), our group has not found significant associations with the APOE-ε4 allele and longitudinal cognition [9], nor did we see any associations with APOE-ε4 and cognition in the present study, despite the fact that APOE is a noted risk factor for cognitive decline [37].