Alzheimer's disease (AD) is the third most expensive disease in the United States, costing society approximately $100 billion each year. It is one of the most prevalent illnesses in the elderly population, and with the aging of society, will become even more significant. Costs associated with AD include direct medical costs such as nursing home care, direct nonmedical costs such as in-home day care, and indirect costs such as lost patient and caregiver productivity. Medical treatment may have economic benefits by slowing the rate of cognitive decline, delaying institutionalization, reducing caregiver hours, and improving quality of life. Pharmacoeconomic evaluations have shown positive results regarding the effect of drug therapy on nursing home placement, cognition, and caregiver time.