Doubts abound about a new Alzheimer’s blood test
Studying beta-amyloids as abnormal proteins that cause Alzheimer’s disease has not translated into a useful drug or therapy. Shutterstock

For the first time, people worried about their risk of Alzheimer’s disease can go online, order a blood test, and receive results in the privacy of their homes. This might seem appealing on the surface, but the development has Alzheimer’s researchers and clinicians up in arms. The Quest Diagnostics blood test, AD-Detect, measures elevated levels of amyloid-beta proteins, a signature characteristic of Alzheimer’s. Introduced in late July, the test is targeted primarily at people 50 and older who suspect their memory and thinking might be impaired and people with a family history of Alzheimer’s ...