More than six million Americans of all ages have Alzheimer’s. About one in ten people age 65 and older has this devastating neurodegenerative disease. While scientists’ understanding of Alzheimer’s has improved dramatically over the past decades, we still don’t know exactly what triggers it. There is presently no cure. A new study is complicating Alzheimer’s further, suggesting that this form of dementia may be a distinctly modern phenomenon. Researchers at the University of Southern California (USC) scoured classical medical texts from ancient Greece and Rome and could barely find mentions of…