The epidemiology of Alzheimer’s disease indicates that 4%–10% of the population over 65 has the disease, and the percentage doubles every 5 years after age 65. In the United States, $174,000 is spent on each Alzheimer’s disease patient; with steadily increasing life expectancy, the number of patients is expected to rise from 9 million to 45 million by 2030. European studies indicate that women are at greater risk than men for developing Alzheimer’s disease after age 85; U.S. studies do not confirm this difference. There is no gender difference for rates and risks for vascular dementia. Interestingly, Native Americans appear to have a significantly lower rate of Alzheimer’s disease, although their aggregate rate of all dementias is similar to that of Caucasians. The economic burden of Alzheimer’s disease varies among countries; cost of illness studies indicate annual per patient costs of $6,500 (England), $24,400 (Sweden), $59,700 (Italy), and $53,300 (United States). Costs increase fourfold from the mild stage of Alzheimer’s disease to the severe stage.