In 2010, there were between 21 and 35 million people worldwide with AD. It most often begins in people over 65 years of age, although 4% to 5% of cases are early-onset Alzheimer's which begin before this. It affects about 6% of people 65 years and older. In 2010, dementia resulted in about 486,000 deaths. It was first described by, and later named after, German psychiatrist and pathologist Alois Alzheimer in 1906. In developed countries, AD is one of the most financially costly diseases.