Into the darkness of the mind.(combination of a U.S.-approved drug called Aricept and a European one known as memantine can be effective in treating Alzheimer's)

When Wayne Huizenga of Blockbuster fame bought the Miami Dolphins football team in 1994, he asked a trusted colleague to write the $127 million check: Gillian Bristol of Florida. Bristol handled financial matters for Huizenga for 26 years, until in early 2000 the math started giving her trouble--not arcane accounting problems, mind you, but simple addition and subtraction. Within months, she was diagnosed with Alzheimer's disease and spiraled rapidly downward. Then in August 2001, her husband, Richard, enrolled her in a clinical trial testing a combination of a U.S.-approved drug called Aricept and a European one known as memantine. Gillian finally began stabilizing and has not declined further in the past year. Is that the result of the drug combo or the unpredictable course of the disease? Doctors don't know. But with the trial long over, Richard continues to buy her both drugs.

In a year of steady progress against Alzheimer's, one of the most concrete developments was the release of data showing how effective this drug combination is. "Now finally we as doctors can tell family members that there is something we can do to slow the disease," says Dr. Barry Reisberg of New York University School of Medicine. And it comes none too soon. Already 12 million people have Alzheimer's worldwide. By 2050, the total could reach 45 million. Will we learn to treat or prevent the ailment in time to reduce that toll? Scientists are optimistic, citing potential new treatments and preventive measures.

The drug combination is a good start. While Aricept boosts low levels of a key brain chemical involved in memory, memantine protects neurons from excessive stimulation by a second brain chemical that can damage or even kill brain cells. But the drugs will not halt the disease. Nor will they address what many scientists see as the actual cause of Alzheimer's--excessive levels of a substance called A-beta, the major constituent of the amyloid plaques that clog patients' brains.

That's why many scientists are excited about the revival of vaccine trials against A-beta. Most people had assumed that the quest for a vaccine was dead two ...