Is it normal for someone to have more than one type of dementia?
A member of the Care Collective asked me this during one of our weekly question and answer sessions, and I figure many of you have the same question. Are people usually diagnosed with just one type of dementia, or with more than one? And would that change the treatment they get, or how the disease gets worse over time?
Dementia Is an Umbrella Term, Not One Disease
Let’s back up for a second. The word dementia isn’t a single disease. It’s really a category.
So if I asked the question a different way, it might sound like this: do most people with cancer have one specific type of cancer, or are they usually diagnosed with more than one? That’s how we think about dementia. It’s a category for conditions that affect somebody’s thinking and their physical functioning.
You may have heard it called an umbrella term. You might even have seen images online of an umbrella with all the specific conditions underneath it: Lewy body dementia, frontotemporal dementia, vascular dementia, Alzheimer’s disease, primary progressive aphasia, and so on. I walk through the main ones in the 5 most common types of dementia.
What Is Mixed Dementia?
Here’s the hard part. Most people are, in fact, officially diagnosed with one type of dementia.
However, mixed dementia, which means more than one type of dementia together, is actually quite common. And it’s probably way underdiagnosed.
How Common Is Mixed Dementia?
Most people will first receive a single type of dementia diagnosis. Usually it’s Alzheimer’s disease, the most common type, with estimates ranging anywhere from 40 to 80 percent of all dementia cases.
Estimates suggest about 1 in 10 people with dementia get a diagnosis of mixed dementia, or dementia due to more than one cause.
The most common combination is Alzheimer’s disease and vascular dementia together.
How a Mixed Dementia Diagnosis Happens
There are two ways it usually comes about.
The first is over time. The person gets a diagnosis of one type, and then at follow-up appointments or follow-up evaluations, the healthcare provider starts to think it’s also looking like another type. That might be based on how they’re doing, how their symptoms are progressing, how their brain scans look, or how they’re doing on neuropsychological testing.
The second is right away. The person is tested for the very first time, and it seems clear on that first assessment that they have more than one type of dementia.
Why Is Mixed Dementia So Hard to Diagnose?
Right now, there is no blood test or brain test that, by itself, lets a doctor definitively diagnose a certain type of dementia. It still takes multiple pieces of information, beyond just a scan or just a blood test.
And many different factors can affect how dementia looks. With all the different types, and how each one shows up in a particular person, it can be really difficult for doctors to feel confident about which type somebody has.
If you’re in the middle of this right now, I go through each step in what I wish I knew sooner about the dementia diagnosis process.
Does Mixed Dementia Change Treatment?
Unfortunately, right now there is no medication that can stop the underlying disease from progressing, regardless of the type of dementia.
There are medications to help with symptoms. There are even more recent medications that can slow down the progression, supposedly. But there’s nothing that can stop it.
So the disease will progress with time, no matter what type of dementia it is. Treatment is largely going to focus on what we can do to manage the symptoms the person is experiencing.
Why Get a Specific Dementia Diagnosis If There’s No Cure?
Sometimes I get a follow-up question: what’s the point of even getting a diagnosis if there’s nothing we can do? If nothing is going to stop it, and there’s no cure, what is the point?
There are lots of reasons getting an official diagnosis is important. Here are two of the main ones.
To Make Sure It’s Not Something Else
We want to make sure it’s not something else. Many other conditions in older age can look like dementia.
The person can be forgetful, have trouble with attention, not want to shower, and seem less interested in things they used to enjoy. Somebody can have all of those symptoms and it’s still not dementia.
To Know What to Expect
The other thing I’ve found for family members is that an accurate diagnosis brings more peace of mind. It helps them understand how the disease may progress and change over time.
Different dementias progress in different ways and on different timelines. It’s not perfect. We can’t guarantee that’s the way it’s going to go. But for the most part, a specific diagnosis gives you a better idea of what to expect as the disease progresses.
Every Person With Dementia Is Different
Remember, every single person is unique. When somebody has dementia, other factors affect how the disease progresses: their other health conditions, the amount of help and support they have, and the other medications they’re on.
Usually when people have dementia, there are many more conditions and health factors involved, and those shape how the decline happens.
Careblazer, thank you for doing everything you’re doing for your loved one.
Working out what a diagnosis means for your family is a lot to sort through on your own. Inside the Care Collective, we hold live question and answer sessions every week, the kind where this question came up. Sometimes they’re with me, and sometimes with experts like an elder law attorney or a nutritionist who works with people with dementia. There are weekly support rooms too, and a community of Careblazers you can reach any time. You can learn more here.
