MAPT and Mental deterioration: Importantly, all associations between tau-PET and cognitive decline remained consistent when additionally controlling for global amyloid-PET (MMSE: β =  − 0.167, T =  − 6.791, p < 0.001, partial R2 for tau-PET = 0.106, partial R2 for amyloid-PET = 0.002; ADAS13: β = 0.211, T = 5.371, p < 0.001, partial R2 for tau-PET = 0.069, partial R2 for amyloid-PET = 0.011; ADNI-MEM: β =  − 0.091, T =  − 3.354, p < 0.001, partial R2 for tau-PET = 0.028, partial R2 for amyloid-PET = 0.003).