Researchers have developed a blood test based on a protein biomarker for tau tangles that can help diagnose Alzheimer’s disease and also provide insight on how far the disease has progressed.

W ith two new treatments for Alzheimer’s disease approved in recent years, there’s growing hope for people at risk of the memory-robbing condition. But tests to detect the condition still lag behind. Earlier diagnosis would mean that people could take advantage of the drugs sooner, when the medicines are most effective.