Defining Mild Cognitive Impairment with Dr. Chin

doctor nathaniel chin
Nathaniel Chin, MD

On October 27th, the NBC drama series This Is Us will return for a fifth season. An integral storyline in the show is the diagnosis of one of the main characters, Rebecca Pearson, with Mild Cognitive impairment (MCI). In this bonus episode, our host Dr. Chin helps define MCI and its potential causes and misconceptions.

Episode Topics:

  • What is Mild Cognitive Impairment? 1:37
  • Difference between MCI and Dementia: 3:29
  • Potential causes for MCI: 4:40

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Intro: I'm Dr. Nathaniel Chin, and you're listening to Dementia Matters, a podcast about Alzheimer's disease. Dementia Matters is a production of the Wisconsin Alzheimer's Disease Research Center. Our goal is to educate listeners on the latest news on Alzheimer's disease research and caregiver strategies. Thanks for joining us.

Nathaniel Chin: Welcome to a special Dementia Matters bonus episode. I do not have a guest with me today, but I want to take the next few minutes defining and explaining terms commonly used to describe memory conditions. From my work in clinic and meeting people in the community, I recognize a lot of understandable confusion stemming from the words we use to describe memory and thinking conditions. Depending on the part of the country where you live, or how your family and friends talk about these conditions, there can be confusion about differences between Alzheimer's disease and dementia, and you surely are not alone.

Today I want to explain mild cognitive impairment. For those that follow the very popular and wonderfully thoughtful show called This Is Us, a main character in this show is diagnosed with MCI, or mild cognitive impairment. The show has done an impressive job of illustrating the struggle for the person with MCI, as well as the family. I'm very appreciative the writers and producers have shined a light on this important condition, because it is not what many people think it is. 

Mild cognitive impairment is an umbrella term we use to describe a set of symptoms. It is a category for which there are many, many types. It is not a specific disease. Let me repeat that. It is not a specific disease. Now specific diseases can cause mild cognitive impairment, but it does not go the other way around. The best example I can give you, and the one I may use later on when we talk about dementia, is a car. We all know what a car is and what it looks like, but you don't just drive your car, you drive a Toyota Prius or a Ford F-150 or a Honda Civic; perhaps you're lucky and you drive a Tesla. Regardless, the Ford Mustang you drive is a specific type of car. Now this is an incomplete definition, but I'll explain why later on. 

So MCI is a category or descriptor term. What it describes is this:  A person with MCI has memory or thinking changes that represent a decline from a higher level they used to be at. This change can be noticed by the person or by those who know the person well. The person with MCI has the courage to undergo extensive memory and thinking tests. And those tests show impairments or scores lower than what would be expected for age. Those impairments, or low scores, are not significant enough that it impairs the person's ability to do their usual daily activities or perform their usual abilities. That's it. That's the definition of mild cognitive impairment. Memory thinking symptoms, low scores on testing, and no impairments on daily activities, such as managing medications, financial matters, driving, cooking, or cleaning. 

MCI is not the same thing as dementia. They are different categories. MCI is not the same thing as Alzheimer's disease. Alzheimer's disease, which I will cover in a future segment, is a disease of the brain that kills brain cells and can cause MCI; but other conditions can cause MCI too, not just Alzheimer's disease. Other brain-derived conditions include Parkinson's disease, Lewy body disease, vascular disease, such as strokes, frontal temporal disease, and normal pressure hydrocephalus. Those things are serious too, but if you have one of them, you want to know which one it most likely is because the treatments can be different, and a person has the right to know what is causing their experience. 

But here's the most important point — MCI can be caused by modifiable or treatable conditions too. MCI can be caused by medications that sedate or negatively affect your brain, by depression, anxiety, bipolar disease by a thyroid disease or obstructive sleep apnea. MCI can be caused by untreated infections or deficient vitamin levels. There are many causes of MCI that if identified and treated could result in improvement in a person's symptoms. Some of the most enjoyable cases I've had in my own memory clinic are when people return to clinic after a year of aggressive treatment for some other ailment and their memory and thinking testing has returned to normal. This happens, and I've seen it. For those who don't return to baseline, I have seen people with MCI stay stable with MCI for decades. They work hard to optimize their health and stay healthy, but their thinking doesn't decline. For those who have MCI due to Alzheimer's disease, I have seen very slow changes in declines happen over time. These individuals are working even harder than the rest to keep their brain performing at its best level. 

The symptoms involved in MCI are different than the diseases that cause it. We may be able to help with symptoms and help with thinking and memory, even if we can't stop the underlying disease right now. And for those who do have a treatable condition, we may be able to actually improve your brain and its performance by targeting that underlying cause. This is why I'm grateful for the This Is Us storyline on MCI, and why I'm doing this segment. Not understanding MCI and the treatable causes of memory and thinking symptoms can lead to unnecessary suffering. If you are worried, please don't hide, please do not be ashamed. There's likely something that can be done. Thank you for listening, and look to my next segment on dementia and how it is different than MCI.

Outro: Dementia Matters is brought to you by the Wisconsin Alzheimer's Disease Research Center. The Wisconsin Alzheimer's Disease Research Center combines academic, clinical, and research expertise from the University of Wisconsin School of Medicine and Public Health, and the Geriatric Research Education and Clinical Center of the William S. Middleton Memorial Veterans Hospital in Madison, Wisconsin. It receives funding from private, university, state, and national sources, including a grant from the National Institutes of Health for Alzheimer's Disease Centers. This episode was produced by Rebecca Wasieleski, and edited by Bashir Aden. Our musical jingle is "Cases to Rest" by Blue Dot Sessions. Check out our website at You can also follow us on Twitter and Facebook. If you have any questions or comments, email us at Thanks for listening.