Dementia is not an inevitable part of the aging process.  Mild memory loss and some slowing down of mental processes often do accompany advanced aging, but they are not symptoms of true dementia.

Dementia is really a name for a set of symptoms, rather than a specific disease.  Dementia can actually take several forms and has several different causes.  Some forms of dementia are temporary, some of its causes are reversible, and in some cases the progress of the condition can be slowed down by medical treatment.  A thorough medical (physical and mental) examination is the important first step in diagnosing and treating dementia.

Dementia is not the same thing as Alzheimer's disease. Alzheimer's disease is a specific illness that causes dementia. Its effects are permanent and its cause and cure are as yet unknown. However, some new drugs have successfully slowed the progression of the disease in a significant number of people.

The prevalence of dementia - and Alzheimer's disease - does increase with age.  Here are some statistics from Dementia.com.

Percentages of people who have some form of dementia (but only about half of them have Alzheimer's disease):

• Less than 2 % of people age 65-69
• About 5 % of people age 75-79
• About 20 % of people age 85-89
• About 33% (one third) of people over 90

It is estimated that about 4.5 million Americans have Alzheimer's disease.  This includes:

• About 5 % of people over 65
• About 20 % of people over 80
• About 30 % of people over 90