What comes first, beta-amyloid plaques or thinking and memory problems?

(American Academy of Neurology) The scientific community has long believed that beta-amyloid, a protein that can clump together and form sticky plaques in the brain, is the first sign of Alzheimer's disease. Beta-amyloid then leads to other brain changes including neurodegeneration and eventually to thinking and memory problems. But a new study challenges that theory. The study suggests that subtle thinking and memory differences may come before, or happen alongside, the development of amyloid p...