Dementia is an inclusive term describing a group of brain disorders that cause memory loss and a decline in mental function. Researchers distinguish two types of dementia, reversible and irreversible dementia. Reversible dementia means the loss of memory can be cured partially or completely with treatment. Irreversible dementia is incurable; patients eventually become unable to take care of themselves and require 24-hour care.

Within the United States, approximately 2 million people have severe dementia, and an additional 1 to 5 million exhibit mild to moderate symptoms. Five to eight percent of people over the age of 65 have some form of dementia and the number doubles every 5 years over age 65. Up to half of those aged 85 and up are expected to contract the disease. These numbers are expected to grow as the baby boomers (individuals born between 1946 and 1964) retire and the “graying” of America accelerates.

Alzheimer’s disease (AD; also known as senile dementia) is the most common form of dementia. Some of its primary hallmarks include memory loss, repeating the same thing repeatedly, having increasing difficulty naming items, and losing things or getting lost more frequently. Other signs are a change in eating habits, an abandonment of hobbies, and the loss of ability to engage in common, everyday activities. The exact causes of Alzheimer’s disease are unknown, though neurofibrillary tangles and betaamyloid plaque are hypothesized as being crucial. Other risk factors include advanced age, head injury, cardiovascular disease, renal failure, and vitamin deficiencies. Alzheimer’s disease is incurable and neurodegenerative (it gets worse over time). Thus, while palliative treatments do exist, no treatment stops or reverses the progression of the disease.

The American Psychiatric Association has established two generally accepted criteria for the diagnosis of dementia, the erosion of recent and remote memory and the impairment of one or more of the following functions: language, motor activity, recognition, and executive function. The diagnosis of dementia also requires that a physician rule out the existence of delirium, a transient, acute mental disturbance that manifests as disorganized thinking and a decreased ability to pay attention to the external world.

There are three stages to Alzheimer’s disease, with the first being the beginning or mild stage. In this stage, AD victims seem healthy, but they are having increasing problems dealing with life (e.g., they cannot find the right word or they engage in uncharacteristic behavior). It often takes time for an observer to realize that something is wrong because the initial Alzheimer’s symptoms are often confused with changes that take place in normal aging. In the second stage, called the moderate stage, the brain becomes more damaged and problems in areas that control language, reasoning, sensory processing, and thought become more prominent. The symptoms and signs of Alzheimer’s disease become more pronounced and behavioral problems can occur in this stage. In the third stage, called the final or severe stage, Alzheimer’s disease sufferers may lose the ability to walk, speak, feed themselves, and recognize others.


  1. Dash, P., & Villemarette, N. D. (2005). Alzheimer’s disease. New York: Demos Medical Publishing.
  2. Gordeau, B., & Hillier, J. G. (2005). Alzheimer’s essentials. New York: Carma Publishing.

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