The nationwide cost of caring for people with Alzheimer’s disease and other forms of dementia soared to $76 billion in 2005. Worldwide, the tab jumped to $315 billion, according to this week’s Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. The international cost reflects a 26% increase in just two years, experts said.

There are 6 million people with Alzheimer’s currently in the United States, 29.3 million worldwide. Both numbers are expected to grow exponentially if a cure or suitable treatment is not found, Alzheimer’s Association officials said. Dementia strikes 1% of individuals aged 60 to 64; the rate leaps to 45% for the 95-plus age cohort.

Drugs now available for Alzheimer’s patients treat only symptoms, but there are nine promising drugs currently in clinical trials for halting the disease, according to the chairman of the Alzheimer’s Association’s Medical and Scientific Advisory Council.