GFAP and Mental deterioration: A recent study on Aβ+ individuals (mean age 73 years) by Mattsson-Carlgren et al. found p-tau217 to be the plasma biomarker most associated with longitudinal cognitive decline.49 Another study by Cullen et al. found that Aβ42/Aβ40 relates to early changes (A), p-tau217 to late changes (T), and NfL to neurodegeneration (N) in the ATN scheme.6 We also found p-tau181 to be an important predictor of cognitive decline most relevant for older individuals (>65 years), whereas for younger individuals (<65 years) GFAP and Aβ42/Aβ40 were the most important biomarkers (Fig. 4).