Revision History

FDA-cleared blood tests measuring p-tau217 and other biomarkers can now detect Alzheimer's disease pathology with over 90% accuracy at a fraction of the cost of PET scans, while new "clock" models can predict symptom onset years in advance. However, as these tests move from research labs into primary care, critical challenges around insurance coverage, health equity, overdiagnosis risk, and healthcare system readiness threaten to limit the impact of what could be the most significant advance in Alzheimer's diagnostics in decades.