The United States on Friday approved the first blood test for Alzheimer’s, a move that could help patients begin treatment earlier with newly approved drugs that slow the progression of the devastating neurological disease.

The test, developed by Fujirebio Diagnostics, measures the ratio of two proteins in the blood. The ratio is correlated with amyloid plaques in the brain—a hallmark of Alzheimer’s that, until now, has been detected only through brain scans or spinal fluid analysis.

“Alzheimer’s disease impacts too many people—more than breast cancer and prostate cancer combined,” said Food and Drug Administration Commissioner Marty Makary.