Alzheimer's disease (AD) is a progressive, neurodegenerative disease that is characterized by the loss of memory, language, and visuospatial skills, poor judgment, and indifferent attitude. Most patients with the disease are age 65 and older, however in some patients, symptoms may begin to appear as early as age 40. The type, severity, sequence, and progression of the changes associated with AD can vary widely, and the early symptoms of AD, which include forgetfulness and loss of concentration, can be easily dismissed as natural signs of aging, the result of fatigue, grief, or depression, or other physical or emotional stressors.

The course of Alzheimer’s disease varies greatly from person to person. Some will have the disease for only the last five years of their lives, while others may suffer for as many as 20 years. And while there are a few medications designed to alleviate the symptoms of AD, there is currently no cure and no way to slow the progression of the disease.

Recently, a group of researchers set out to estimate the prevalence of Alzheimer’s disease in the American population from 2000 through 2050. The results of this study were published in the August 2003 issue of the Archives of Neurology. The researchers concluded that as longevity rates increase and death rates decrease, the number of people with AD in the US will rise dramatically unless new discoveries are made to prevent this illness.

About the study

The researchers estimated the incidence of Alzheimer’s disease by applying data from three adjacent, urban, biracial (black and white) neighborhoods in south Chicago to US census bureau estimates of population growth.

To do this, the researchers conducted two in depth, at home interviews approximately four years apart in 3838 people who were determined to be free of AD at the beginning of the study. In the end, 835 people were evaluated for AD.

The findings

The researchers determined that in 2000, there were approximately 4.5 million people with AD in the US. Based on their estimates, by the year 2050, this number will increase almost three-fold to 13.2 million. The greatest increase will occur among those who are over age 85, whose incidence of AD will quadruple to approximately eight million. The next largest increase will be among people between the ages of 75 and 84. Their incidence rate will double to approximately 4.8 million. Only the incidence rate for those between the ages of 65 to 74 years old will remain fairly constant at 0.3 to 0.5 million.

This dramatic increase is most likely due to the fact that the death rates among people over age 65 in the US are expected to decrease by as much as 50% by 2050. This considerable drop will first, increase the number and proportion of persons who survive to the ages where AD is most frequent, and, second, result in increased survival of persons with AD.

How does this affect you?

The study suggests that over the next 50 years, the prevalence of AD in the US population will increase substantially, and that the majority of the people living with the disease by that time will be over 85 years of age.

Because AD places a heavy burden on the health care system and profoundly affects the health and well being of both those who develop the disease and their caretakers, it is an important component of long range public health care planning.

This study presents a significant public health challenge to both the US government and the medical community. They must work together to make these projections obsolete by discovering better, more effective methods of treating this disease and working diligently to find a cure. As our nation continues to age, the quality of life of our grandparents, our parents, and ourselves is at stake.