Mild cognitive impairment

Mild cognitive impairment (MCI) is a term used to describe early memory and thinking problems in older people. It is not a disease in itself.

While many people have a natural decline in memory and thinking as they get older, people with MCI experience difficulties that are greater than expected for their age. However, these difficulties tend not to get in the way of a person’s day-to-day life.

MCI can be caused by a range of underlying conditions and may or may not get worse. One cause of MCI can be the early stages of Alzheimer’s disease or another form of dementia. However, other conditions such as depression, low vitamin levels and thyroid problems can also cause similar mild memory difficulties.

Some people with MCI find that their symptoms stay the same or return to normal. MCI does not necessarily lead to dementia.

We do not have a clear picture of how many people have MCI. Research has suggested that one or two in every 10 people over 65 may have MCI or cognitive impairment. However, it is not always easy for a doctor to diagnose MCI, so it’s hard to know exactly how many people are affected.

What’s the difference between MCI and dementia?

The word dementia describes a group of symptoms that can affect a person’s ability to carry out daily activities without help. These include memory problems, confusion and mood changes. A person with dementia will usually experience two or more of these symptoms, such as problems with their memory or getting lost. Someone with MCI may have only one of these symptoms and unlike dementia, it would not normally interfere with their day-to-day life.

Does MCI lead to dementia?

Having MCI raises your risk of developing dementia in future, even if your symptoms get better over time. However, it’s not yet clear how many people with MCI go on to develop dementia.

Some studies estimate that each year, 10-15% of people with a diagnosis of MCI develop dementia. Other studies have put this figure as low as 5-10%. For people who do develop dementia, the time this takes can vary from one person to another.

Factors such as older age, depression, diabetes or high blood pressure may increase the likelihood that someone with MCI will go on to develop a form of dementia like Alzheimer’s disease. People with MCI who have a risk gene called APOE4 have a higher risk of developing Alzheimer’s. Having this gene may also increase the risk of developing MCI in the first place.

This information was written in January 2018 and is due to be reviewed in November 2019. Please contact us if you would like a version with references.

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