School of Medicine researchers Barry Reisberg, M.D., and Steven Ferris, Ph.D., led an important multicenter study showing that a drug that quashes the activity of a key brain chemical slows the mental and physical deterioration of patients with moderate to severe Alzheimer’s disease. The new study, published in the April 3 issue of the New England Journal of Medicine, involved 32 medical centers nationwide and enrolled 252 patients.

The drug, memantine, is the first effective treatment for patients in the later stages of Alzheimer’s disease, says Dr. Reisberg, Professor of Psychiatry and Clinical Director of the William and Sylvia Silberstein Aging and Dementia Research and Treatment Center. Dr. Ferris is the center’s Executive Director and the Gerald J. and Dorothy R. Friedman Professor of the Alzheimer’s Disease Center.

“These patients seem to be declining much less, about half as much as ordinarily expected, over a six-month period,” says Dr. Reisberg. “This medication slows down the otherwise inexorable progress of Alzheimer’s, and it is remarkably free of side effects. These are very impressive results. It looks like this drug really will have an impact on this disease.”

Alzheimer’s disease is the most common form of dementia affecting people over age 65. Some 4 million Americans have the mind-robbing disease, a major reason why people are institutionalized.

In the moderate to severe stages, patients begin to lose the ability to care for themselves. They have trouble dressing and bathing; many can no longer make a cup of coffee or tea. “This is also the time when there is an increase in behavioral disturbances, and when the burden on caregivers intensifies as they struggle to care for a loved one who is slipping away,” says Dr. Reisberg.

The treatments for Alzheimer’s available in the United States are aimed at a chemical system in the brain called the cholinergic system. They strengthen the activity of neurons that use the brain chemical acetylcholine to transmit their signals. However, these treatments are effective only in the mild to moderate stages of the disease. There are no treatments available for slowing the later stages of Alzheimer’s.

Memantine blocks the activity of a brain chemical called glutamate, which excites neurons, some of which are involved in learning and memory. In recent years, researchers have discovered that when neurons become overstimulated because of an abundance of glutamate, they can become damaged or die, and this “excitotoxicity” has been linked to the death of neurons in the brains of patients with Alzheimer’s. “Meman­tine is a completely different chemical way of getting at the disease,” says Dr. Reisberg.

If approved by the FDA, memantine would be the first therapy available in the United States for the more advanced stages of Alzheimer’s disease.

“This study,” says Neil Buckholtz, Ph.D., Chief, Dementias of Aging Branch at the National Institute on Aging, “shows that treatment in the very late stages of Alzheimer’s disease can be beneficial.”