Revision History

A landmark UC San Diego study published in JAMA Network Open shows that the blood biomarker p-tau217 can identify women at up to seven times greater risk of developing dementia as many as 25 years before symptoms emerge. The research, which tracked 2,766 women from the Women's Health Initiative Memory Study, arrives as the first FDA-cleared Alzheimer's blood tests enter clinical use — but raises critical questions about the ethics of presymptomatic screening and whether early detection can be paired with effective prevention.