Research also is under way to see if estrogen reduces the risk of Alzheimer's disease or slows the disease. One study showed that estrogen does not slow the progression of already diagnosed disease, but more research is needed to find out if estrogen may play another role. For example, scientists now are trying to find out whether estrogen can prevent Alzheimer's disease in women with a family history of the disease.

Estrogen and progesterone combination therapy is not recommended for prevention of cognitive decline or dementia. In one large national study of women 65 and older, Prempro, a specific form of combination hormone therapy, was found to double the risk of dementia in women on combination therapy when compared to those not taking the medication.

Recent research suggests that ginkgo biloba, an extract made from the leaves of the ginkgo tree, may be of some help in treating Alzheimer's disease symptoms. There is no evidence that ginkgo will cure or prevent Alzheimer's disease. Scientists now are trying to find out whether ginkgo biloba can delay or prevent dementia in older people.

People with Alzheimer's disease and those with mild cognitive impairment who want to help scientists test new treatments may be able to take part in research studies, otherwise known as clinical trials. These research studies are done on people to find out whether a new drug or treatment is both safe and effective.

New therapies are tested on people only after laboratory and animal studies show promising results. The Food and Drug Administration sets strict rules to make sure that people who agree to be in the studies are treated as safely as possible.

Scientists have come a long way in their understanding of Alzheimer's disease. Findings from years of research have begun to clarify differences between normal age-related memory changes, mild cognitive impairment, and Alzheimer's disease. Scientists also have made great progress in defining the changes that take place in the Alzheimer's disease brain, which allows them to pinpoint possible targets for treatment.

These advances are the foundation of the National Institutes of Health's Alzheimer's Disease Prevention Initiative, which is designed to

• understand why Alzheimer's disease occurs and who is at greatest risk of developing it.

• improve the accuracy of diagnosis and the ability to identify those at risk.

• discover, develop, and test new treatments.

• discover treatments for behavioral problems in patients with Alzheimer's disease.

1. At present, there is no cure for Alzheimer's disease.

TRUE is the correct answer. There is no cure for Alzheimer's disease, but there is hope. Scientists learn more every day about the disease, and there are now four drugs available -- Cognex®, Aricept®, Exelon®, and Razadyne® -- which can provide modest relief for mild symptoms in the early and middle stages of the disease. There are also drugs available to control the behavioral symptoms associated with the disease.

2. Research shows that vitamin E can slow the progress of Alzheimer's disease.

TRUE is the correct answer. Research has shown that vitamin E can slow the progress of some consequences of Alzheimer's disease by about 7 months. Scientists are now studying vitamin E to learn whether it can prevent or delay Alzheimer's disease in a person with mild cognitive impairment, or MCI.

3. Research has shown that ginkgo biloba can prevent Alzheimer's disease.

FALSE is the correct answer. There is no evidence that ginkgo will cure or prevent Alzheimer's disease. Scientists now are trying to find out whether ginkgo biloba can delay or prevent dementia in older people.

4. The purpose of a clinical trial is to determine if a new treatment will be beneficial.

TRUE is the correct answer. Clinical trials are research studies on people to find out whether a new drug or treatment is both safe and effective. New therapies are tested on people only after laboratory and animal studies show promising results. The Food and Drug Administration sets strict rules to make sure that people who agree to be in the studies are treated as safely as possible.