Dementia vs Alzheimer's Disease: Are They the Same Thing? Does it matter?

The terms “dementia” and “Alzheimer’s disease” are often used interchangeably, but there's actually an important difference between them that can affect care.

In order to understand the distinction, we need to understand this statement: Alzheimer's disease is always dementia, but dementia is not always Alzheimer's disease.

Let's dig into the term dementia to start with. When we say someone has dementia, it means that they're displaying a certain set of symptoms. For instance:

• Memory loss
• Difficulty concentrating
• Finding it hard to carry out familiar daily tasks, such as getting confused over the correct change when shopping
• Struggling to follow a conversation or find the right word
• Being confused about time and place
• Mood changes

If this is all we know, then we know what is happening, but we don’t know why. It's kind of like saying that someone with the following symptoms has a “bug.”

• Runny nose
• Coughing
• Congestion
• Fever
• Fatigue

The above “bug” symptoms could result from many different illnesses. You might have a common cold, the flu, pneumonia, Covid, a sinus infection, bronchitis, or allergies.

You know the symptoms, but until you have an actual diagnosis you won't know whether you need antibiotics, allergy medications, or some other remedy.

So the term “dementia” describes the set of symptoms. “Alzheimer's disease,” on the other hand, is a diagnosis. A diagnosis tells us why the dementia is happening.

Although Alzheimer's disease is the most common cause of dementia in older adults, there are many others that require different treatments, just like a physician will treat the flu in a different manner than allergies.

This is particularly important to understand when the onset of dementia is sudden, because many causes of sudden dementia are reversible if treated. In this case, you should ask:

• Did a medication change?
• Is your loved one experiencing severe depression?
• Are they dehydrated?
• Is it possible that they had a stroke?

There are many more possible causes: the most important thing is get a medical evaluation right away.

Perhaps the most common cause of reversible dementia is, believe it or not, urinary tract infections. When dementia comes on quickly, this should always be on the list of things to check right away.

Alzheimer's disease is an irreversible dementia. Other examples of irreversible dementia include Parkinson's disease, Lewy body dementia, traumatic brain injury, or dementia brought on by the long-term use of alcohol abuse or exposure to other substances that have a negative effect on brain function.

When we know why dementia is happening, we have better options for how to understand the circumstances and respond more effectively.

Even when it is an irreversible dementia, we can better emotionally prepare ourselves for the road ahead. We can also make the best use of the time we are given.

If you’d like more detailed information about dementia and Alzheimer’s disease, you can check out my free online course, What Is Dementia? It expands on the topics I’ve covered here.