Many people develop depression in the latest stages of life, but until now doctors had no idea that it could point to a build up of a naturally occurring protein in the brain called beta-amyloid, a hallmark of Alzheimer's disease. In fact, late-life depression could become a major risk factor for developing Alzheimer's faster than others, according to research.

Many people develop depression in the latest stages of life, but until now doctors had no idea that it could point to a build up of a naturally occurring protein in the brain called beta-amyloid, a hallmark of Alzheimer's disease. In fact, late-life depression could become a major risk factor for developing Alzheimer's faster than others, according to research.