“And if dementia is one of the most dreaded forms of decline associated with aging, it is also one of the most common. The condition affects about 14 percent of people over age 71. The prevalence of dementia increases with age, rising from about 5 percent among people in their 70s to 24 percent of those in their 80s – and of those who reach age 90, approximately 40 percent are affected.”
—Taylor, Janelle. “How being friends with someone who has dementia can be good for you both.” The Conversation. July 6, 2017.