Between 1990 and 2040, the United States elderly population is expecte
d to grow from 31.6 to 68.1 million. In order to assess the implicatio
ns of this increase on the mortality from neurodegenerative diseases i
n the United States, we used Census Bureau population estimates to for
mulate projections of the annual number of deaths from neurodegenerati
ve diseases and from six comparison conditions (liver cirrhosis, colon
cancer, lung cancer, cancer of the female breast, multiple sclerosis,
and malignant melanoma), assuming that the United States disease-age-
gender-race-specific death rates for 1985-1988 remain constant between
1990 and 2040. We find that neurodegenerative disease mortality incre
ases by 119-231%, depending on the model of population growth used. Fo
r the 'middle' population growth model, the increase in annual neurode
generative disease mortality is 166%. The major component of this incr
ease is the rise in deaths attributed to dementia. For the six compari
son diseases, the increases in mortality range from 52 (multiple scler
osis) to 130% (colon cancer). Given the current level of underascertai
nment of neurodegenerative disease mortality and the conservative natu
re of the Census Bureau estimates of future population, it is likely t
hat these projections are underestimates. The implications of these da
ta are discussed.