What Is Mild Cognitive Impairment (MCI)? Symptoms, Causes, Diagnosis, and Treatment

Mild cognitive impairment (MCI) is an early stage of memory loss or other loss of cognitive (thinking) function — for example, losing memory or language skills — beyond what would be expected at a person’s age or level of distraction or as a result of poor sleep or anxiety.

People with MCI are able to perform daily activities without assistance, according to the Alzheimer’s Association. In some people, though, symptoms progress to a stage that requires assistance with daily activities.

The causes of MCI aren’t completely understood. In some people, symptoms may be the result of changes in the brain linked to the early stages of Alzheimer’s disease or other conditions that cause dementia (advanced cognitive impairment accompanied by functional impairment).

You’re more likely to develop MCI as you get older, and your risk is greater if you have a genetic variant linked to Alzheimer’s disease. A report from the Alzheimer’s Association estimates that for adults ages 60 to 64, the rate of MCI is 6.7 percent, and this rate increases to 14.8 percent for adults ages 75 to 79 and 25.2 percent for those ages 80 to 84.

Your risk for MCI may also be greater if you have certain medical conditions, including diabetes, high blood pressure, or depression, according to Mayo Clinic. Other factors that can play a role include a lack of physical activity, a lower education level, and a lack of mentally engaging or social activities.

A diagnosis of MCI is based on your symptoms and may be guided by a number of different mental assessments, as well as a neurological examination and screening for other conditions like depression. If you’re diagnosed with MCI, you may also undergo certain tests that can show whether your MCI is related to Alzheimer’s disease.

Depending on whether your MCI is related to Alzheimer’s disease, you may be eligible for certain drugs approved for early-stage Alzheimer’s, the Alzheimer’s Association notes.

MCI is characterized by forgetfulness. But it’s important to understand what “forgetting” means in this context.

It’s not entering your bedroom and forgetting that you were looking for your keys. That’s an attentional and focus problem, caused by moving from one location to another. Nor is it getting worse at facial recognition or having the word you want at the “tip of your tongue” more frequently. Both of these symptoms happen with normal aging.

Doctors who concentrate in this area define forgetting as not being able to recall details of events, forgetting entire events, and failing to recall information that you paid attention to, necessitating repeated questions.

Forgetting by this definition is not a normal part of the aging process. Starting to become more forgetful or have other thinking difficulties to a greater extent than your normal could be a sign of MCI, according to the National Institute on Aging.

The following issues may be signs of MCI, according to Mayo Clinic:

• Forgetting things more often
• Losing items more often
• Asking repeated questions
• Being unable to follow the story in a book, show, or movie
• Having difficulty following a conversation

While you may notice some of these symptoms yourself, it’s also possible that you won’t but family or friends will.

It’s important to take signs of MCI seriously, but that doesn’t mean every misplaced item or forgotten word is a sign of the condition. The following issues may arise as part of the normal aging process, according to the National Institute on Aging:

• Forgetting to make a monthly payment
• Occasionally forgetting what word to use
• Losing items once in a while
• Forgetting what day it is, but remembering later
• Making bad decisions now and then

If these kinds of issues start to become more frequent, though, it may be a good idea to see your doctor for a cognitive evaluation.

Other symptoms, on the other hand, may indicate more advanced cognitive impairment than MCI. The following issues may be signs of dementia, according to Alzheimers.gov:

• Losing items often
• Forgetting to go to important events
• Difficulty having a conversation
• Trouble with reading or writing
• Repeating a question or story several times
• Difficulty with basic daily activities
• Difficulty managing money or paying bills
• Getting lost in familiar places
• Making lots of poor decisions
• Losing track entirely of the date or time or year

If you — or a friend or family member — have any of the problems listed above, it’s important to see a doctor for a cognitive evaluation so that you or they can get the help you or they need, the National Institute on Aging notes.

MCI may be caused by neurodegenerative changes in the brain — such as the beginning stages of Alzheimer’s disease or other conditions that cause dementia — or by reversible issues like sleep disorders, medical conditions, or depression. Since depression is believed to be widespread in older adults, it’s important for people with symptoms of MCI to be screened for the condition, the Alzheimer’s Association notes.

When MCI is linked to neurodegenerative changes, the following factors most strongly predict MCI, according to the Alzheimer’s Association:

• Older age
• Family history of Alzheimer’s or another type of dementia
• Cardiovascular risk factors (such as high cholesterol or blood pressure)

Another factor that increases the risk for MCI is having a genetic variant known as APOE-e4, according to Mayo Clinic. This gene is linked to developing Alzheimer’s disease as well, but having the variant that increases your risk doesn’t necessarily mean you’ll develop any cognitive problems.

The link between age and MCI can be seen in a report published by the Alzheimer’s Association, which estimated the following rates of MCI in different age groups of older adults:

• Ages 60 to 64: 6.7 percent
• Ages 65 to 69: 8.4 percent
• Ages 70 to 74: 10.1 percent
• Ages 75 to 79: 14.8 percent
• Ages 80 to 84: 25.2 percent

Other health-related factors that increase the risk for MCI include:

• Diabetes
• Obesity
• Obstructive sleep apnea
• Smoking
• Inadequate physical activity

A low education level and not participating in mentally or socially stimulating activities are also linked to MCI, the Mayo Clinic notes, but causal links have not been established.

Drinking alcohol does not clearly increase the risk of developing MCI. Nonetheless, people with MCI who drink more alcohol may be at greater risk for further cognitive decline. One study found that among over 3,000 participants ages 72 and older, those with MCI who reported typically having more than 14 drinks per week were 72 percent more likely to develop dementia during a median follow-up period of six years than those who had less than one drink per week.

Certain prescription drugs can contribute to impaired memory, especially in older adults. It’s important for your doctor to take any such drugs into account when evaluating you for MCI, since it’s not considered to be MCI if it’s a drug side effect. The following drugs are known to be linked to memory issues, according to the UCSF Weill Institute for Neurosciences:

• Benztropine (Cogentin)
• Diazepam (Valium)
• Diphenhydramine (Benadryl), also found in Advil PM and Tylenol PM
• Lorazepam (Ativan)

There isn’t a single test used to diagnose MCI. Instead, your doctor will base a diagnosis of MCI on a number of factors — including the information you provide about your symptoms, as well as the results of any cognitive assessments that you undergo.

Many doctors base a diagnosis of MCI on the following criteria, which have been developed by a panel of experts on the condition, according to Mayo Clinic:

• Problems with memory or another cognitive function
• Decline in mental function over time
• Daily activities not affected by cognitive issues
• Cognitive testing showing mild impairment
• No diagnosis of Alzheimer’s or another type of dementia

Cognitive Testing

Your doctor may ask you to complete a short type of mental status testing to help diagnose or rule out MCI. This test will most likely take about 10 minutes, and involves following various written instructions. Commonly used tests include the Short Test of Mental Status, the Montreal Cognitive Assessment (MoCA), and the Mini-Mental State Examination (MMSE).

If your doctor wants more information about your mental status, you may be asked to complete a more detailed cognitive assessment. A more comprehensive test can help determine how much your memory or another mental function is impaired, including which specific areas of your memory may be affected.

Your cognitive test scores will take into account not just your performance, but also your age and education level, Mayo Clinic notes. If your cognitive performance is somewhat lower than would be expected of someone at your age and education level, that may help support a diagnosis of MCI.

Neurological Exam and Other Tests

As part of evaluating your mental status, your doctor may perform some basic tests as part of a neurological exam. These tests may include testing your reflexes, eye movements, walking, and balance — all of which can be affected by health conditions that also affect your mental function, such as Parkinson’s disease, a stroke, or a brain tumor, Mayo Clinic notes.

The following aspects of your neurological health may be evaluated in a basic neurological exam, according to Johns Hopkins Medicine:

• Mental Status Your doctor may ask you questions, paying attention to both the content of your response and whether your speech is clear and flows easily.
• Motor Function and Balance You may be asked to push and pull against your doctor’s arms with your legs or arms, as well as stand or walk in a certain way. Your doctor may also ask you to move or lift your arms or legs, tap your fingers or foot, or perform basic movements with your eyes closed (such as touching your nose).
• Sensory Function Your doctor may test your ability to feel using tools like dull needles, tuning forks, or alcohol swabs. This may involve asking you to identify a sensation on your arm or leg as hot, cold, sharp, or dull.
• Reflexes Your doctor may tap various points on your body with a reflex hammer to test your body’s automatic reaction.

Depending on what symptoms you report and whether your doctor suspects certain health conditions based on your neurological exam, your doctor may also order tests for things like thyroid function or vitamin B12 deficiency. If your doctor suspects a serious problem with your brain, you may be asked to undergo imaging tests like an MRI or CT scan, Mayo Clinic notes.

Not everyone with MCI will continue to lose cognitive function and receive a diagnosis of Alzheimer’s disease or another type of dementia. The National Institute on Aging estimates that over the course of a year, 10 to 20 percent of people ages 65 and over with MCI go on to develop dementia. But in many cases, symptoms of MCI stay the same or even improve.

According to a report published by the Alzheimer’s Association, among people diagnosed with MCI due to the early stages of Alzheimer’s disease, 30 to 50 percent will go on to develop Alzheimer’s dementia during a period of 5 to 10 years. Progression to dementia may be more likely for people with MCI that mostly affects memory rather than another cognitive function.

In many cases, no specific treatment is recommended for MCI. But if your MCI is found to be due to an early stage of Alzheimer’s disease, certain treatment options may be available. There are also lifestyle measures that may help slow the progression of, or even reverse, certain symptoms of MCI.

Treatment of MCI

A couple of treatments have been approved for early stages of Alzheimers’s disease:

• lecanemab (Leqembi)
• donanemab (Kisunla)

These treatments have been shown to help remove a marker of Alzheimer’s known as beta-amyloid plaques from the brain and improve overall cognitive function, according to the Alzheimer’s Association. Since there are specific diagnostic criteria, these treatments aren’t right for everyone with MCI.

If you have MCI, you should be reevaluated every six months to see if your symptoms have progressed and determine whether any treatments are right for you.

Lifestyle Measures for MCI

Certain aspects of your lifestyle may help slow or reverse cognitive decline in people with MCI, although the results of research in this area are mixed, according to Mayo Clinic. These lifestyle measures include:

• Regular exercise
• Eating lots of fruits and vegetables
• Limiting saturated fat in your diet
• Consuming omega-3 fatty acids (such as in a fish oil supplement)
• Keeping your brain active through activities like playing games, reading, or hobbies
• Having an active social life
• Memory training exercises

According to a recently published research review, lifestyle areas that are linked to progression of MCI and Alzheimer’s disease include a poor diet, stress, nutrient deficiencies, not getting enough sleep, worse mental health, lack of social activity, and exposure to toxins.

Complementary and Alternative Treatments

There hasn’t been much research on whether dietary supplements or other alternative treatments may help slow cognitive decline in people with MCI. Limited evidence suggests that supplements like vitamin E or ginkgo may be helpful, according to Mayo Clinic.

But there are many quacks and frauds out there trying to sell supplements that supposedly improve memory or “support” brain health.

To save yourself both money and disappointment, talk to your doctor before trying any such supplements. And even if you’re willing to take the risk of trying unproven supplements, you’ll want to run them by your doctor to make sure there isn’t a medical reason you shouldn’t take them, such as an interaction with a medication you take.

Since poor sleep is believed to accelerate cognitive decline, improving sleep in people with MCI has been an active area of research. In a review of relevant studies, researchers found that a variety of interventions were found to help improve sleep time or quality in people with MCI or early-stage dementia — including psychotherapy techniques, the insomnia drug suvorexant (Belsomra), transcranial stimulation (a noninvasive brain stimulation technique), and melatonin.

RELATED: Sleep 101: The Ultimate Guide to a Better Night’s Sleep

Not every case of MCI can be prevented, but there are steps you can take to maintain your cognitive health as you get older, as noted by the American Academy of Family Physicians:

• Maintaining a healthy body weight
• Managing diabetes, high cholesterol, high blood pressure, and obesity
• Eating plenty of fruits, vegetables, and whole grains
• Avoiding unhealthy fats
• Getting enough omega-3 fatty acids (such as in fatty fish and fish oil)
• Staying physically, socially, and mentally active
• Not drinking alcohol in excess

Older adults who report feeling a sense of purpose in life are less likely to experience cognitive decline, according to the National Institutes of Health. So any steps you can take to feel connected and valued in your family and community may also be good for your brain health.

The following organizations and online resources offer information and support for people with MCI:

National Institute on Aging

Learn more about MCI and about clinical trials on treatments for MCI. You can also sign up for a weekly email with tips and resources on Alzheimer's disease and related dementias. The page Memory, Forgetfulness, and Aging: What's Normal and What's Not? may be of particular interest.

Alzheimer’s Association

The Alzheimer’s Association offers information on MCI as well as a 24/7 helpline, local support groups, and an online community.

Alzheimers.gov

In addition to basic information about MCI, Alzheimers.gov offers links to further information and to a clinical trial finder.

AARP

The AARP website has a number of articles aimed at individuals with MCI or dementia and their family caregivers.