MCI vs. dementia: Here’s one easy way to tell the difference

There are a lot of things that are frustrating and confusing and vexing about mild cognitive impairment.

But if there’s one question I see people with MCI struggling with more than any other, it’s this one.

What is the difference between MCI and dementia, and how can a doctor tell?

That is a very confusing thing to understand, and a very hard thing to explain.

But I just heard one of the top neurologists in the country explain it in a way that was just so clear and so simple, I had to share it with you.

Hi, I’m Tony Dearing, of, the website for people with mild cognitive impairment.

Many people with MCI, probably most people with MCI, when they first got their diagnosis, they found it baffling.

MCI? What is it? I’ve never heard of it? Do I have dementia? Am I’m going to get dementia? What’s the difference between MCI and dementia anyway?

All good questions, and ones that can be extremely hard to answer. Frankly, some doctors just aren’t that good at explaining it. I know people with MCI who felt they understood less about their condition after it had been explained to them.

So it’s really a blessing when you can find a doctor who can take a very complex medical issue and lay the answer out in a way that is so clear and simple that anybody can understand it.

One like Dr. Bradford C. Dickerson, a Harvard neurologist who I just saw do that on the question: How do you tell the difference between MCI and dementia?

Now to begin with, there really is a difference, and there really are ways to tell. What Dr. Dickerson has found is a way to demystify that. So bear with me as I walk you through this, because by the time I’m done, I think you might have a clearer understanding of that.

So MCI is not a form of dementia. MCI is really just a catch-all term that says you have a loss of memory or other thinking skills that’s worse than expected for someone your age.

That’s what MCI means. Your memory loss isn’t normal. There’s something going wrong here. But you don’t have dementia, and it doesn’t mean you’re going to get dementia. Most people with MCI don’t progress to dementia.

Still, you are at higher risk, and understandably, you want to know, How can I tell? How can a doctor tell? Where is the line between MCI and dementia, and how do they know when someone has crossed it?

There is a line. It’s a fuzzy line, but it’s there. And it involves doing a functional assessment of what are called “activities of daily living.”

So what the hell does that mean, right? It’s one of those terms that doctors understand, but it’s meaningless to the average person.

What we’re talking about here is the ability to do daily tasks. Balancing your checkbook. Driving a car. Knowing to put a coat on when its cold outside. Being able to bathe yourself or feed yourself.

God knows, MCI can be hard to live with, very difficult, very frustrating. But people MCI still manage to do most of these daily tasks on their own. People with dementia need assistance with these things, and the more severe the dementia, the more help they need.

So that’s the dividing line between MCI and dementia, and obviously, that’s not a sharp line. There’s a gray area. It can be hard to tell when someone has crossed over that line.

That’s where Dr. Dickerson comes in. He has found a simple rule of thumb that doctors can use and families can use to help determine when that line has been crossed.

This is something he shared in a recent training video for physicians, offered by MD Magazine.

In the video, Dr. Dickerson starts out by saying it’s “very important” to be able to distinguish between MCI and dementia, and that the “threshold varies from person to person.”

However, he tells doctors that one simple question can help provide the answer.

He tells physicians, “What I like to ask people is, if you, as the care partner, can leave the person and go on a trip for a weekend or a week, would they function independently at things that they need to try to get done to get by in daily life?”

“If the care partner says, ‘No, I would never do that,’ you can pretty comfortably say that the person probably has crossed the threshold into dementia.”

OK, so let’s be clear about this. This is a rule of thumb. It’s not a clinical tool. It’s not a diagnosis. It’s an indicator. But a very, very helpful indicator that real people in the real world can use to understand the difference between MCI and dementia, and where a person might be in the progression, if they’re progressing.

It’s the best answer I’ve seen yet to one of the most urgent questions facing people with MCI. It’s something doctors can use and it’s something that you can watch for, and keep an eye on, too. I hope you find it helpful.

And I hope you join me again next week. Until then, as always, be kind to your mind.

The full MD Magazine video featuring Dr. Dickerson is below.

Print Friendly
  1. Jim Ruane says

    Neuropsychological testing over time (2-3 yrs) can detect the difference between MCI and dementia definitively. I am 77 yrs old and was diagnosed with MCI a year ago, but I know I do not have dementia through testing this last September. Also, since dementia progresses about 4% per year and I f I do develop Alzheimer’s, it’s not likely to impact my life significantly.

    • tony Dearing says

      Thanks for the great comment, Jim. I appreciate you describing your experience, and what you have to say can help other people. Through this testing you’ve been through, you have gained an advantage that many people with MCI don’t have. You know what you’re dealing with, and you know it’s not Alzheimer’s. I’m sure you were relieved to find that out, and I’m happy for you. Your perspective is a valuable one, and I thank you for sharing it with others.