In comparison to APOE 3/3, the most common APOE genotype, APOE4 is found in about 25% of the population and in about 60% of persons with the clinical and neuropathological diagnosis of AD, with each additional allele copy associated with a higher risk and earlier age at onset of AD biomarker changes, cognitive decline, and dementia.1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Here, APOE is linked to Mental deterioration.