MAPT and Mental deterioration: Baseline tau PET uptake was differentially linearly related to the annual rate of cognitive decline in Aβ(+) and Aβ(-) individuals (interaction t = 4.275, p < 0.001); the association was statistically significant in Aβ(+) individuals (95% confidence interval 2.07–3.09), but not in Aβ(-) individuals (95% confidence interval -1.19–1.04) (Fig. 4E).