What is the outlook for Alzheimer's Disease ?
In very few families, people develop AD in their 30s, 40s, and 50s. This is known as "early onset" AD. These individuals have a mutation in one of three different inherited genes that causes the disease to begin at an earlier age. More than 90 percent of AD develops in people older than 65. This form of AD is called "late-onset" AD, and its development and pattern of damage in the brain is similar to that of early-onset AD. The course of this disease varies from person to person, as does the rate of decline. In most people with AD, symptoms first appear after age 65.
                
We don't yet completely understand the causes of late-onset AD, but they probably include genetic, environmental, and lifestyle factors. Although the risk of developing AD increases with age, AD and dementia symptoms are not a part of normal aging. There are also some forms of dementia that aren't related to brain diseases such as AD, but are caused by systemic abnormalities such as metabolic syndrome, in which the combination of high blood pressure, high cholesterol, and diabetes causes confusion and memory loss.