Many people use the terms “Alzheimer’s Disease” and “dementia” interchangeably.  However, these terms are not different names for the same disease.   Indeed, dementia is not a disease at all, but symptoms that signal an underlying problem with the brain.  Since some causes of dementia are treatable, it is important for anyone who suspects that he or she is declining in cognitive ability be evaluated by a physician.

What is Alzheimer’s Disease?

The behavioral attributes of Alzheimer’s Disease include (1) loss of short term memory, (2) increasing need for assistance in performing normal daily activities due to mental confusion, and (3) inability to organize, plan or follow directions.  The clinical hallmarks of Alzheimer’s Disease include ABeta protein accumulations in the brain, often described as plaques, development of tau protein within the neurons, known as tangles, and diminished brain size.  Scientists do not know what causes the body to generate high levels of protein, or how these proteins impair normal brain activity.  However, researchers know that over time, those with high levels of ABeta and Tau are likely to show the behavioral attributes of Alzheimer’s, and to experience brain atrophy, initially affecting the hippocampus region of the brain, and spreading to other areas of the brain.

What is Dementia?

By contrast, dementia is not a disease, but a constellation of symptoms that indicate the presence of an underlying problem with the brain.  Clinicians define dementia as 1) memory loss and 2) trouble with at least one other common cognitive function, such as planning, problem solving, or organization, which makes it difficult or impossible to operate normally.

Therefore, someone with Alzheimer’s Disease will exhibit the symptoms of dementia.  However, not everyone with dementia has Alzheimer’s Disease.

Causes of Dementia

People with symptoms of dementia could have any one of the following medical problems:

• Alzheimer’s Disease
• Stroke
• Parkinson’s Disease (Lewy Body Disease)
• Picks Disease
• Brain injuries due to accidents or repeated physical impact to the head
• Thyroid malfunction
• Vitamin deficiencies
• Adverse drug reactions
• Brain tumors

Why is it important to know what is causing the dementia?

Some causes of dementia are treatable, such as thyroid malfunctions, vitamin deficiencies, and adverse drug reactions.  Therefore, it is important to rule out, or treat, those causes of dementia which have effective therapies.

Even if the cause of dementia is not treatable, it is helpful to pinpoint the cause because different causes may have additional symptoms and needs.  For example, those with Lewy Body dementia may react negatively to medication commonly given to those suffering from Alzheimer’s Disease.  Knowing the underlying cause of the dementia can lead to more effective therapies and strategies for enhancing the quality of life.

For more information on the different types of dementia, an excellent guide can be found here.