The number of Americans diagnosed with Alzheimer's disease is expected to more than triple from today's 4.6 million by 2050, according to researchers.

Dr. Denis Evans, professor of medicine at Rush-Presbyterian-St. Luke's Medical Center in Chicago, presented the new forecast at a news conference at the eighth International Conference on Alzheimer's Disease and Related Disorders in Stockholm.

Evans said the new numbers, slightly higher than those he projected a decade ago, are based on a study of 6,158 people in Chicago. The new estimate ranges from 11 million people on the low end to 16 million on the high end.

"The projected increase in numbers of people with Alzheimer's disease is not due only to the total number of people alive, but to the substantially increased survival of people with the disease," Evans said.

The increase in Alzheimer patients will drive health care costs -- currently estimated to run some $100 billion a year -- into the stratosphere. And with no federal or state program to pay the costs of nursing home care for Alzheimer patients, the financial burden will fall primarily on the children of these patients, researchers warned.

"The study on Alzheimer's prevalence and those on the costs related to Alzheimer's underscore the urgent need for more research into the causes, prevention and treatment of this devastating disease," said Stephen McConnell, chief executive officer of the Alzheimer's Association.

The Association is urging the U.S. Congress to increase federal funding of Alzheimer's research to $1 billion annually.

"We must find the answers before these projections become a reality," McConnell said.

Other sources: International Conference on Alzheimer's Disease