Mild Cognitive Impairment: The Essential Facts

James M. Ellison, MD, MPH

Swank Center for Memory Care and Geriatric Consultation, ChristianaCare

  • Expert Advice
Published on:
A close-up of a senior gentleman's face who has mild cognitive impairment.

Learn the facts about mild cognitive impairment, including how it is diagnosed and why early recognition is very important.

A lot of my friends worry about memory loss – it’s only natural, we’re all getting older! But I am afraid I have something worse than normal aging! I notice it especially at work, where I usually have to juggle a few different projects and sometimes I’ll completely forget about one of them. I’ll give you an example, doctor…wait a minute, I know I had a perfect example to give you! Well, that’s part of what happens.”

Robert,* a physically healthy, 64-year-old accountant, was accustomed to using his brain to the fullest at work and at home. In his work, he had to absorb a lot of new information quickly, work with it, analyze it, and explain what he found in a clear way. Often he had to manage several tasks at once and to switch flexibly between them. He had no difficulty living independently, dressing and feeding himself, shopping, driving, and getting himself to work every day. His wife noticed that he seemed more withdrawn and worried. He had become less talkative. He had begun to carry around a little notebook of lists and reminders, which was a new habit. One day he accidentally left his notebook home, and missed his scheduled dentist appointment. Robert was probably more attentive than most people to changes in his ability to focus and shift his attention or to use his memory.  He asked the memory clinic to help him figure out whether he was experiencing normal aging or something more.


Let’s take a moment to discuss terminology. Up until 2013, the Diagnostic and Statistical Manual (DSM), which lists all the different psychiatric conditions, contained only one name for progressive cognitive decline, and that was “dementia.” The most recent definition of dementia, dating from the early 1980’s, became outdated as researchers and clinicians saw how dementia usually develops over decades. There is a period, sometimes lasting for years, during which memory or other cognitive functions are more impaired than in normal aging, but not so damaged yet as to warrant a diagnosis of dementia.  

The 5th edition of the DSM (DSM 5) replaced the term “dementia” with “major neurocognitive disorder.” The DSM 5 also added a new term to describe cognitive impairment worse than normal aging but not severe enough to be called major neurocognitive disorder. That term is “mild neurocognitive disorder (MiND).”

Many researchers and clinicians, however, still talk about “mild cognitive impairment (MCI),” which was the name that they had begun to use to describe this problem even before there was an official diagnostic term.

MCI was originally described as a condition in which a person’s cognitive abilities had slipped enough to result in significant changes on standardized tests but not enough to interfere greatly with usual social and occupational activities. The affected person, or someone who knew them, would usually be aware of this, but most other people would not notice a problem. Some people with MCI complained mostly of difficulty with memory, some had problems with the ability to reason and solve problems, while others had multiple areas of difficulty.

Are MCI and MiND the Same?

The DSM 5’s definition mild neurocognitive disorder (MiND) is similar to MCI but has a slightly different focus. The diagnosis of MiND requires the presence of one or more measurable cognitive difficulties. The areas evaluated are as follows:

  • Complex attention refers to the ability to sustain focus and switch between tasks.
  • Memory includes recall of recent and more remote events as well as of how to do things.
  • Executive function is the ability to reason and solve problems.
  • Language includes both expression and understanding in spoken and written forms.
  • Visuospatial cognition is the ability to understand such things as shapes, locations, and directions.
  • Social cognition is the ability to recognize the meaning of others’ facial expressions and behavior so that we can interact successfully.

The key point in differentiating MiND from normal aging at one end and dementia at the other is that the person’s difficulties must not be severe enough to interfere with independence, even though they are troublesome enough to require effortful behaviors to maintain normal functioning. The person with MiND manages by using reminders, lists, and other “workarounds” or compensatory behaviors.

Robert’s increasing difficulty with task-shifting and his new need for reminders suggested a problem beyond normal cognitive aging. The loss of his train of thought in the middle of a sentence can happen to anyone once in a while, but much more often in someone with MiND.

Recognizing MiND is Important

Early recognition of a cognitive change can allow a person and those in his or her life to search for a remediable cause. Medication side effects, excessive use of alcohol, depression, sleep disorders, and many medical conditions can interfere with cognitive functioning. Early treatment can get someone back on track.

Sometimes, though, MiND is the first sign that a progressive disorder like Alzheimer’s disease is developing. In those cases, early recognition can help a family prepare for the future and seek the best treatment available. Sometimes that will include participation in a research clinical trial.

Researchers have been very interested in MiND because earlier treatment can be more effective. The idea of early treatment is to interfere with the development of amyloid plaques and neurofibrillary tangles, the brain changes associated with Alzheimer’s disease before they have spread throughout the brain. That seems likely to be more effective than trying to remove them after they have already destroyed brain cells.

Diagnosing MiND

Clinical examination and history lead to the diagnosis of MiND. Neuropsychological testing can help identify how much cognitive change is present and whether it is more than expected for a person of similar age and education. Blood tests, MRI, sleep assessments, or other special tests may identify a specific disease process responsible for cognitive changes. Some new, experimental tests such as the amyloid PET scan can identify the presence of amyloid plaques in the brain at a very early stage, even before major neurocognitive disorder is clinically present.

Developing a Plan

When MiND is present, an affected person and his or her family may need to plan for the future. Over the next few years, important decisions will need to take this condition into account. Retirement or a change in job responsibilities may be necessary for someone still employed. Driving safety should be evaluated. A family may want to make sure that an affected person is managing finances thoughtfully and not making impulsive decisions or forgetting to do what’s necessary. Over the longer term, it may be helpful to review residential needs and consider whether adequate supports can be provided in a person’s home. If not, long-term care facilities can offer help with the basic needs of daily life.

Robert was evaluated carefully. His history, physical examination, blood tests, and sleep evaluation showed him to have a few treatable conditions: sleep apnea, mild depression, and a vitamin deficiency. When these were treated, his focus improved significantly. He had an amyloid PET scan and was pleased to learn that it did not show the presence of the plaques linked with Alzheimer’s disease. He will be followed clinically to make sure that no progressive disorder is developing. Because of his good self-awareness and his clinicians’ attention to these treatable conditions, Robert is doing much better now. *Robert is a fictitious person whose story is made up of several other people’s symptoms in order to protect anonymity.

About the author

Headshot of Dr. James Ellison

James M. Ellison, MD, MPH

Swank Center for Memory Care and Geriatric Consultation, ChristianaCare

James Ellison, MD received his medical degree from UCSF in 1978 and trained in psychiatry at the Massachusetts General Hospital (1979-1982).

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