Alzheimer's Tests: Pros & Cons Of The Six Main Options First, the bad news: No single test can tell with certainty if someone has Alzheimer's disease. If that surprises you, you're not alone. Almost half of adults surveyed in five countries believed a reliable Alzheimer's test exists, according to a 2011 survey by the Harvard School of Public Health and Alzheimer's Europe. Now the good news: Exciting research developments mean an Alzheimer's diagnostic test is nearer than ever. That's because probable signs of the disease now can be found in . . .