What Causes Dementia?

The terms "Dementia" and "Alzheimer's Disease" are often used interchangeably, but they are not the same thing. Alzheimer's is one known cause of dementia but there are at least four others. Each involves the loss of memory and the impairment of cognitive functioning (the ability to perceive things accurately, to think clearly and to act with deliberate consciousness) to a degree that impairs a person's daily life.

The process of differential diagnosis - determining what the cause of the dementia is - can play an important role in developing helpful interventions and treatment. The five major types of dementia currently used in the medical/psychiatric communities. Each one can include or not include behavioral problems and/or delirium, a state of acute and intense confusion. The diagnosable types of dementia include:

1. Dementia of the Alzheimer's Type

Alzheimer's Disease is a specific physiological condition where the cells of the brain begin to deteriorate. It is a progressive disease that often begins slowly and tends to accelerate over time. Contrary to some popular misconceptions, Alzheimer's is NOT a normal part of aging. In the long run, Alzheimer's Disease is fatal and while there are some treatments that have been shown to slow down the advancement of the disease, there is currently no known cure for it.

In this type of dementia, the cognitive impairments are the direct result of the physical illness damaging and killing formerly healthy brain cells. Alzheimer's Disease is the most common cause of dementia.

2. Vascular Dementia

In this type of dementia, the memory loss and cognitive impairments are caused by problems with the flow of blood through a person's vessels. Blockages or slow-downs of the flow of blood in key places can, over time, lead to dementia. This is not a single disorder nut more accurately a grouping of many specific syndromes all involving the flow of blood through the human body and all causing, if not treated early on, dementia.

Unlike Alzheimer's, Vascular Dementia can be prevented and, at least at its early stages, treated by intervening to allow for a better flow of blood. These interventions can be either surgical or medicinal in nature. There is a measurably increased correlation between hypertension and vascular dementia as there is between elevated blood pressure and stroke.

The symptoms appear the same, but the cause and available treatments are different.

3. Dementia Due to Other Medical Conditions

This type of dementia is where the disorder is caused by specific other medical conditions. These can include (but are certainly not limited to) Parkinson's disease, traumatic brain injury, HIV infection, Huntington's disease, hypothyroidism and brain tumor.

The presentation is very much like that with dementia from any other cause. The importance of differential diagnosis here is of the essence. The treatment strategy is often to go after the underlying medical condition first to see if the symptoms of dementia can be at least partially ameliorated in that way. It is not possible to make good diagnosis of any variety of dementia without a thorough medical work-up.

4. Substance-Induced Persisting Dementia

Both prolonged drug abuse of illegal substances or excessive use of alcohol as well as of certain prescribed medications can cause dementia to develop. The diagnosis is made by ruling out other causes and by establishing the fact of substance-related loss of memory and debilitated cognitive functioning. Even once substances are stopped, the damage caused in the form of dementia is likely to remain.

Dementia, no matter what the cause, is not regarded as a reversible or fully curable condition. Its progression can be slowed by treating the underlying conditions but once the damage is done, it is done.

And finally,

5. Dementia Due to Multiple Etiologies (causes)

As with so many things about life, the cause of dementia cannot always be accurately ascribed to one thing. Dementia caused by Alzheimer's, vascular problems, other medical conditions or substances are simply not mutually exclusive.

All types of dementia have two key elements in common. Firstly, there is an impairment of memory (a reduced ability to learn new information or to recall previously learned information) and; Secondly, there is at least one major disturbance in cognitive functioning (aphasia, apraxia, agnosia, executive functioning, etc.) See the links below for further information about these terms and their significance.