What Is Dementia?
Some people may ask, "What is dementia?" Many do not understand that it is not a specific disease. It is a descriptive term for a collection of symptoms that can be caused by a number of disorders that affect the brain. While the symptoms are often associated with Alzheimer's disease, many different conditions can cause these symptoms. A healthcare provider makes a diagnosis when two or more brain functions -- such as memory, language skills, perception, or cognitive skills (including reasoning and judgment) -- are significantly impaired without loss of consciousness.
A woman in her early 50s was admitted to a hospital because of increasingly odd behavior. Her family reported that she had been showing memory problems and strong feelings of jealousy. She also had become disoriented at home and was hiding objects. During a doctor's examination, the woman was unable to remember her husband's name, the year, or how long she had been at the hospital. She could read but did not seem to understand what she read, and she stressed the words in an unusual way. She sometimes became agitated and seemed to have hallucinations and irrational fears.
This woman, known as Auguste D., was the first person reported to have the disease now known as Alzheimer's disease (AD) after Alois Alzheimer, the German doctor who first described it. After Auguste D. died in 1906, doctors examined her brain and found that it appeared shrunken and contained several unusual features, including strange clumps of protein called plaques and tangled fibers inside the nerve cells.
Memory impairments and other symptoms of dementia, which means, "deprived of mind," had been described in older adults since ancient times. However, because Auguste D. began to show symptoms at a relatively early age, doctors did not think her disease could be related to what was then called "senile dementia." The word "senile" is derived from a Latin term that loosely translates to "old age."
It is now clear that Alzheimer's disease is a major cause of dementia in elderly people as well as in relatively young adults. Furthermore, we now know that Alzheimer's disease is only one of many disorders that can lead to dementia.
Although Alzheimer's disease and certain other conditions are technically causes of dementia, they are also often referred to as types of dementia. Likewise, terms such as "vascular dementia" are often used to describe causes as well as types.
Besides senile dementia, other terms that are often used to describe dementia include senility and organic brain syndrome. Senility and senile dementia are outdated terms that reflect the formerly widespread belief that it was a normal part of aging. Organic brain syndrome is a general term that refers to physical disorders (not psychiatric in origin) that impair mental functions.
Research in the last 30 years has led to a greatly improved understanding of:
- What dementia is
- Who gets it
- How it develops and affects the brain.
This research is beginning to pay off with better diagnostic techniques, improved treatments, and even potential ways of preventing these diseases.
(Click Dementia Research for more information about research being conducted on this topic. To learn more about strategies that may help prevent symptoms, see Dementia Prevention.)