ABSTRACT
In the past century, life expectancy has increased more than 27 years. As the number of elderly
persons has dramatically increased, Alzheimer’s disease (AD) has become one of the major public
health problems in the United States and the entire developed world. The “prevalence and
malignancy of AD,” as described in a two-page editorial written in 1976 by Dr. Robert Katzman (1),
has become well known to physicians as well as the lay public. In the editorial, Katzman estimated
the prevalence and mortality due to AD, and placed AD as a leading cause of death in the United
States. Hebert has shown that the impact of AD will be ever more dramatic over the next 50 years as
the numbers of very elderly in the population rise at an accelerated rate (2). Projecting age-specific
prevalence data for AD to the population distributions obtained from the U.S. Census Bureau, there
were 4.5 million cases of AD in the United States in the year 2000 and there will be 13.2 million in
the year 2050.