Figure 1.

Schema for Mediation Analyses. An initial structural equation model estimated the c path, which is the total direct effect of the predictors on the outcome. Next, the same direct path was estimated (c’) while simultaneously estimating mediation effects (indirect pathway a × b). The total effect is the sum of direct and indirect pathways for a predictor. Mediators included 1) harmonized MMSE/MoCA scores, or 2) harmonized neuropsychological tests: Story Recall, Naming, Animal Fluency, and Trail Making Test Part B. Note: 42-Residue-Long Amyloid β Isoform (Aβ1–42); Neuropsychiatric Inventory Questionnaire (NPI-Q); Tau Phosphorylated at Threonine-181 (p-tau181).