APOE and Cognitive impairment: One prior study using mediation analysis to evaluate the indirect pathway from which APOE alleles impact late-life cognitive impairment via cerebrovascular lesions, AD-pathology, and non-AD neuropathologies was conducted using autopsy data from 1671 individuals who had a different sociodemographic profile compared to our sample (93.2% of APOE-ε4 carriers were White and had a mean education of 16.8 years).