Patients say they want Alzheimer's blood tests. Doctors aren't sure they help.

Key Points:

• Alzheimer’s blood tests measure amyloid or tau proteins that accumulate in the brain decades before symptoms, but their accuracy in predicting who will develop the disease remains debated among doctors.
• There is currently no cure for Alzheimer’s, and FDA-approved drugs only slow progression with mixed efficacy and serious side effects, raising questions about the practical benefits of early testing.
• A recent survey found 85% of adults would take an Alzheimer’s blood test if recommended by a doctor, despite many expecting distress from positive results and skepticism about test validity among some experts.
• The FDA has approved two blood tests for symptomatic individuals, but these tests are not diagnostic on their own and carry risks of false positives and negatives, limiting their current clinical use.
• Experts acknowledge improvements in blood testing technology and see potential for future diagnostic and treatment-monitoring applications, but emphasize that the tests are not yet reliable enough to be used alone for diagnosis.