Mild Cognitive Impairment (MCI)

Mild cognitive impairment (MCI) happens when you experience a slight — but noticeable — decline in mental abilities compared to others your age. Mental abilities include:

• Memory.
• Reasoning and judgment.
• Planning and completing complex tasks.

You may notice the decline in your abilities, or a loved one might. But the changes aren’t severe enough to interfere with daily, routine activities of life.

What’s the difference between mild cognitive impairment and mental decline due to aging?

It’s natural and expected to have some gradual mental decline as you age. For example, learning new information may take longer than before. Or your speed of performance may get slower.

But these declines due to aging don’t affect your overall functioning or ability to perform daily activities. Normal aging doesn’t affect recognition, intelligence or long-term memory.

As you age beyond 65 years, you may occasionally forget names and words and misplace things. With mild cognitive impairment, you frequently forget conversations and information that you would typically remember, like appointments and other planned events. MCI interferes with your daily, routine activities.

What’s the difference between dementia and mild cognitive impairment?

Both dementia and MCI are descriptive terms that tell us about the degree of cognitive change and how it affects daily activities. The main difference between MCI and dementia is that the mental decline in MCI doesn’t interfere with daily living, whereas dementia does. In addition, people with MCI don’t experience personality changes that people with dementia can. Many underlying conditions can lead to MCI or dementia.

Dementia involves a decline in mental function from a previously higher level that’s severe enough to interfere with daily living. A person with dementia has two or more of these specific difficulties, including a decline in:

• Memory.
• Reasoning.
• Language.
• Coordination.
• Mood.
• Behavior.

Does MCI always lead to dementia?

Some people with MCI eventually develop dementia, but others don’t. For certain neurodegenerative conditions, MCI can be an early stage of the condition. Neurodegenerative conditions affect your brain and get worse over time. Alzheimer’s disease and Parkinson’s disease are examples of this. Some people with MCI return to normal cognition for their age or remain stable.

How common is mild cognitive impairment?

The American Academy of Neurology estimates that mild cognitive impairment is present in the following populations:

• 8% of people aged 65 to 69.
• 15% of people aged 75 to 79.
• 25% of people aged 80 to 84.
• 37% of people 85 or older.