Who is affected? On the basis of comparisons of large groups of
people with Alzheimer's disease with others who have not been
affected, researchers suggest that there are a number of risk
factors. This means that some people are more likely to suffer
from the disease than others. However, it is unlikely that the
disease could be traced to a single cause. It is more likely
that a combination of factors lead to its development, with the
importance of particular factors differing from one person to
another. About one person out of twenty over the age of 65
suffers from Alzheimer's disease and less than one person in a
thousand under the age of 65. However, it is important to note
that although people do tend to become forgetful as times goes
on, the vast majority of people over 80 stay mentally alert.
This means that although the likelihood of suffering from
Alzheimer's disease increases with age, old age does not itself
cause the disease. Nevertheless, recent evidence suggests that
age related problems such as