GFAP and Mental deterioration: The correlation observed between cognitive decline and plasma pTau181, GFAP, and NfL in the present study (with longer follow‐up) is in keeping with findings in DLB that plasma GFAP, NfL, pTau181, and pTau231 are associated with decline in cognition,4, 5 although a smaller DLB cohort found no association between these markers and cognitive decline.15