Know the 7 stages of cognitive impairment

Every now and then, I do a post that blows up on me. Like say, for instance, one from a couple of weeks ago.

The headline was: “Mild cognitive impairment versus dementia: One easy way to tell the difference”

I knew there would be a lot of interest in it, because this is one thing that people with MCI often find quite confusing. What is MCI? What is dementia? How can doctors tell the difference?

That’s what I answered two weeks ago, and it immediately became one of the most read posts that I’ve ever published.

It got a lot of reaction, and led to a lot of additional questions, including this one:

What are the stages of cognitive impairment and dementia, and where does MCI fit in those stages?

That’s a great question, and one I think that it can help anyone with MCI to understand. So today, let’s address that.

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

I am always in favor of increasing your MCI IQ. MCI can be a baffling, frightening condition. The better you understand it, the less frightening it becomes and the readier you are to address it.

So today, let’s demystify the stages of cognitive decline. There are seven of them, and this is something we’ve understood dating back to the 1980s.

Stage 1 is normal cognition. Your memory seems fine. You don’t have any concerns.

Stage 2 is called Subjective Cognitive Impairment. Something doesn’t seem right. Your memory is starting to slip. You’re worried, your family is worried.

Stage 3 is Mild Cognitive Impairment. You’ve been to the doctor, you’ve been tested, and it shows that there is a problem. You have a degree of memory loss or some other cognitive problem that’s outside the norm of someone your age.

At this stage, you do not have dementia. MCI is not a form of dementia, although it does leave you at higher risk for dementia.

Now this is where I want to pause. Because there is a lot of confusion over MCI and dementia, and I think that this is one of the places where people with MCI get particularly confused. And that confusion is around what comes next.

Because there are two possible paths out there, and what comes next depends on which path you’re on. So let me show it that way. What you see here are two paths, and most people with MCI are on the path on the left. For them, the path ends here. This is as far as they go.

Now I have some statistics that I’ve shown you before, but I want you to see them again. They come from a 2019 study of nearly 900 people with MCI, who were followed over a period of five years.

It showed:

  • 53 percent stabilized at MCI
  • 35 percent reverted to cognitively normal or fluctuated between MCI and cognitively normal
  • And only 12 percent progressed to dementia

Now let’s go back to the two paths. Let’s say we’ve got 50 people with MCI. Statistically speaking, 44 of them are on a path that only has three stages, and ends at MCI. They’re either going to stabilize at mild cognitive impairment or improve.

Six of them are on the second path, the one that has seven stages. They’re progressing to dementia, and the final four stages are:

  • Mild Dementia
  • Moderate Dementia
  • Moderately severe Dementia
  • Severe Dementia

I’m not going to get into a lot of detail on these four stages of dementia. This is an MCI site. We focus on MCI here. And for people with MCI, what we focus on actions that offer the best possible chance of slowing, halting or reversing that cognitive decline while it is still at Stage 3, the MCI stage.

Many people with MCI are able to stop it here because the thing that’s causing their cognitive problems is treatable.

A vitamin deficiency. A thyroid condition. A bad reaction to medication. Depression. Anxiety. Hearing loss. Alcohol abuse. Lack of exercise. A poor diet.

These things can be addressed, either by medical treatment or by lifestyle changes or both. And if they are, cognition can stabilize or even improve.

And that is the real reason I wanted to put the 7 stages in context for you. Not to scare you with the final four stages

But to emphasizing how good the odds are of being able to get and stay on the path that ends at MCI, giving yourself the best odds of stopping it while you still can.

How do you do that? Well, that’s what I’m here every week talking about. To show you what you can do, and how you can do it.

I know you’re making the effort, and I applaud you for that. Keep it up. Fight for you cognition. I hope you’ll join me again next week. Until then, as always, be kind to your mind.