The word "dementia" derives from Latin and means quite literally "without mind". Medically, it is an umbrella term used to describe a decline in a number of brain activities that include memory loss.
Dementia is marked by a pattern of mental decline. This is usually a gradual decline, although sometimes the decline can be sudden.
At present, 6 to 7 million Americans have some form of dementia, and an estimated 15 percent of people older than 65 are thought to suffer from dementia. Alzheimer's disease
is the most common cause of dementia, affecting more than 12 million Americans over the next 20 years.
Dementia is a progressive disease with gradual onset that worsens over a number of years. Initially, symptoms are subtle and begin with memory loss. Gradually, more cognitive function is lost. This decline continues until even the most basic mental and physical functions are difficult to perform. As dementia progresses, a person may lose his or her ability to recognize friends and family, think critically, perform complex tasks and, in some cases, the ability to speak.
In most cases, dementia is incurable. The life expectancy of a person with dementia
depends on the underlying cause. It can vary from months to years. Rarely, dementia is caused by a treatable condition (such as a metabolic disorder or depression). In these cases, treatment of the underlying condition may significantly improve symptoms of dementia.