In 2017, an estimated 5.5 million Americans were diagnosed with Alzheimer disease (AD) and 200,000 under 65 years of age are described as having early-onset AD. Even more striking is the finding that 47 million Americans are presymptomatic with stage I AD. These dire statistics beg the question about the merits of getting tested for AD since lifestyle changes can help people at risk, but they are less likely to improve the conditions of those already experiencing cognitive impairment or dementia.
