Is memory loss a normal part of growing old?
As you get older, your brain ages along with the rest of your body. As a natural part of the aging process, you will lose some of your mental ability. Because this change is generally gradual, pinpointing the exact age when mental ability declines is difficult. Researchers know that after age 50, episodes of memory loss occur more frequently.

However, this normal decline in mental function should not interfere with your ability to function in your daily life. In contrast, any drastic or sudden change in memory function may be indicative of an underlying disease. If this occurs, contact your doctor or other health-care professional for evaluation. He or she will assess any significant change in memory, personality, behavior, language or analytic skills.

How does memory change with age?
Age-related memory loss is a highly active area of research. There are many ways to assess memory, including written tests, verbal exercises and practical tests for specific tasks. What researchers know with certainty is that:

Does a decline in memory indicate dementia?
Dementia is an umbrella term used to describe significant decline in a number of brain activities that include memory loss. Some degree of age-related memory loss is normal. In people with dementia, the changes in memory are significant enough to affect the ability to function in daily life. In addition to memory loss, patients with dementia show changes in personality and behavior.

What causes dementia?
In some cases, dementia is caused by treatable conditions, such as:

In these cases, dementia may be partially or entirely reversed if diagnosed and treated early. Evaluation by a health care professional will include testing to see if any of these conditions are contributing to mental decline.

However, most causes of dementia are not curable. This type of irreversible dementia commonly results from the degeneration or interruption of brain neurons (the connections in the brain). This can have a variety of causes:

What is Alzheimer's disease?
Alzheimer's disease is a progressive, degenerative brain disease. It initially affects memory, but as the disease progresses, it involves many other brain functions. It eventually leads to physical illness and, ultimately, to death. Characteristic changes occur in the brains of people with Alzheimer's disease. These changes cannot be detected by current laboratory tests. With time, tests may become available to diagnose the disease and to determine whether or not a person will develop it.

Can I inherit Alzheimer's disease?
A few patients with Alzheimer's disease (about 3 percent) have a genetic abnormality that is believed to be the cause of their disease. This abnormality is in the chromosomes — the genetic material that you inherit from your parents. A specific abnormality in one of these chromosomes will result in Alzheimer's disease. Researchers refer to this as autosomal-dominant inheritance because a defect in just one chromosome can result in the disease, which is passed from one generation to the next. This is a rare form of Alzheimer's disease that affects young patients. It is best to think of Alzheimer's as a disease of the elderly.

What treatment is available for Alzheimer's disease?
Alzheimer's disease affects a system of signal transmissions in the brain that is known as the cholinergic system. Medications have been developed to restore cholinergic function. There are four medications approved by the U.S. Food and Drug Administration (FDA) for the treatment of Alzheimer's disease that act on the cholinergic system. These are:

Although these medications do not offer a cure, they can improve the symptoms of mild to moderate dementia.

Another drug, memantine (Namenda), works differently than the drugs listed above. Memantine is approved for the treatment of moderate to severe Alzheimer's disease.

In studies of patients with moderate to severe Alzheimer's disease, those who took Namenda by itself showed a slower decline in mental function when compared with those who took placebo (a sugar pill). In a separate study, those who took Namenda in combination with donepezil (Aricept) vs. donepezil alone, also showed a slower decline in mental function.

Treatment of the complications of Alzheimer's disease, including behavioral disorders, depression and sleep disturbances, requires careful assessment of social and environmental issues and the exclusion of other medical causes. Treatment should initially involve lifestyle changes. Should this fail, medications can then be considered.