MAPT and Mental deterioration: There is, however, some support that HV is associated with cognitive decline and progression more strongly than t-tau.13, -, 15 Although in our study we found t-tau as individual biomarker also predicted clinical progression and cognitive decline, the high correlation with p-tau hampers the addition of t-tau to a model with Aβ and p-tau, making it a less desirable biomarker to use in the AT(N) classification.