We determined (i) whether tau-PET is superior to demographic variables and plasma pTau217 to predict cognitive decline in those with elevated plasma pTau217 levels (to determine whether tau-PET has any added value in this pTau217-positive population), and (ii) whether tau-PET has no or minor predictive value in those patients with low plasma pTau217 levels (who would not be selected for tau-PET). This evidence concerns the gene MAPT and Mental deterioration.