Commentary on “A roadmap for the prevention of dementia II: Leon Thal Symposium 2008.” A federally funded corporation for the prevention and treatment of cognitive impairment and brain aging

People with cognitive impairment, including Alzheimer’s disease, represent a progressively worsening health, economic, and societal crisis of enormous proportions. The crisis will expand with the increasing and longer-living United States population as more people develop cognitive or intellectual impairment. For example, there are half a million new Alzheimer’s disease cases in the United States per year, a prevalence of 5.5 million that will increase to 7.7 million by 2030 [2]. More than half will be older than the age of 80 years; a substantial proportion are in late middle age. Alzheimer’s disease, however, is only the most evident tip of the crisis because it is the end stage of, on average, a slowly progressive intellectual and nerve cell deterioration coursing over decades. At the time people are diagnosed with very mild or early Alzheimer’s disease or mild cognitive impairment, they have experienced substantial brain cell loss and are far advanced in their cognitive difficulties, impaired in many areas of intellectual, social, and daily activities. Alzheimer’s disease garners most attention because its expression is most extreme, but it does not represent most cognitive impairment. Cognitive impairment associated with aging, including mild cognitive impairment and cerebrovascular cognitive impairment, are each nearly as prevalent as Alzheimer’s disease. Traumatic brain injuries caused by