What is the Definition of Dementia?

If taken literally, the definition of dementia is “madness”, but although in some cases, this is a fair description of how the disease affects the brain, it is probably not politically correct these days to refer to a patient with dementia as “mad”.

Once upon a time, dementia was more commonly referred to as “senile dementia”, but this term is not used now as it implies that the affected person is old, which is not necessarily the case. However, dementia is more common in older people and the older we get, the more likely we are to be affected by dementia: 50% of people 85 and older have dementia.

What is the definition of dementia?

The Diagnostic and Statistical Manual of Mental Disorders (DSM) used to place a heavy emphasis on memory loss as the main symptom of dementia, but its definition has since been refined to define dementia as being more of a general decline in cognitive and intellectual function.

These days, dementia is usually used as an umbrella term that covers a number of different diseases and health issues affecting a patient’s brain. In broad terms, dementia is a serious deterioration in cognitive ability, which causes a patient to lose their reasoning skills, language, and the ability to perform simple tasks like getting dressed or eating. But although dementia is typically associated with aging, it is possible to suffer from the effects of dementia for a variety of other reasons, including an injury to the brain or diseases such as Alzheimer’s.

In many cases, dementia causes a very gradual decline in levels of reasoning and intellectual function. The person might suffer from memory problems to begin with, and then as the disease progressively destroys brain cells, memory loss is followed by personality changes and behavioral problems. However, occasionally the symptoms of dementia arise from a sudden incident such as a stroke or brain injury, and in such instances, the problems associated with dementia develop almost immediately. The symptoms of dementia can also be caused by drug and alcohol abuse, or hormone imbalances.

What is the definition of dementia for the purposes of making a diagnosis?

Classic symptoms of dementia include memory loss, changes to personality and mood, loss of language skills, inability to understand or learn new information, confusion, hallucinations, paranoia, and eventually an inability to manage even the simplest of tasks. However, in order for a patient to be classed as suffering from dementia (whatever the underlying cause might be), the loss of cognitive function must be significant enough to cause major interference with normal life.

What is the definition of mixed dementia?

Mixed dementia is when the symptoms of dementia are caused by more than one disease or health problem. For example, a patient may be suffering from Alzheimer’s, but subsequently have a stroke whereby further damage is caused by an interruption to the blood supply in the brain. So although it is often assumed that dementia has only one cause, in practice there are often many contributory factors that are causing the dementia symptoms, which can make the correct diagnosis very difficult.