Nearly one in five Americans over the age of 60 experience subtle downturns in memory, thinking, and cognition. Clinically, this fading of cognitive abilities is called mild cognitive impairment (MCI).

MCI can sometimes turn into something more serious. 

One in six people living with MCI eventually go on to develop dementia. The good news is that it’s more likely that people living with MCI will recover. One in four people with MCI get back to their usual level of cognition. Figuring out and treating the underlying cause or causes of a person’s MCI symptoms could help find a treatment to reverse it.

So what causes MCI? 

MCI as an early sign of Alzheimer’s or other forms of dementia

Sometimes MCI is a sign of the very early stages of neurodegenerative diseases, like Alzheimer’s, or other forms of dementia. In this case, the symptoms are caused by problematic proteins that clump and tangle which interrupts brain signaling and kills individual brain cells. The best-known of these proteins are beta-amyloid and tau — two of the key hallmarks of Alzheimer’s disease. After a cognitive screening, a specialist might recommend a PET scan or MRI. If the scans don’t spot these proteins, the doctors can rule out Alzheimer’s. 

Currently, there is no surefire way to reverse this type of MCI caused by Alzheimer’s. Scientists are hoping the new class of drugs that targets beta-amyloid plaques can make the difference. The results suggest that Leqembi—which received accelerated approval earlier this year—may slightly slow the rate of cognitive decline. The hope is that future drugs will be able to reverse MCI entirely.

Other causes of MCI 

Mild cognitive impairment could be a sign of many other conditions. If untreated, these other causes could also increase the risk of developing dementia. Cardiovascular disease causes the narrowing of arteries, damages blood vessels, and makes it harder to supply nutrients and oxygen to the brain. In this case, lowering blood pressure and cholesterol through exercise, dietary changes, and medications like statins may reverse MCI.

Traumatic brain injury and stroke damage specific parts of the brain, leading to cognitive and memory problems. In some cases, the cognitive changes can be rehabilitated. However this depends on the severity of the injuries. 

Some people with insomnia experience MCI. Sleep deprivation and disruptions prevent the brain from resting and recharging. Working with a doctor to improve sleep quality can help reverse this type of MCI. 

The hormonal shifts occurring during menopause could lead to MCI. Treatment with hormone replacement therapy can reduce many menopause symptoms, including cognitive impairment. 

As many as three in five people diagnosed with depression will experience some form of memory loss or cognitive impairment. Treating the underlying depression with a combination of medications and therapy can alleviate these symptoms.

What does MCI feel like?

Some forms of MCI only affect memory. This is called “amnestic MCI”. People might forget previous conversations, or misplace items like wallets and keys. 

In other cases, MCI affects parts of the brain that aren’t related to memory causing difficulty with speech or language, trouble focusing, and difficulty navigating familiar spaces.

Lifestyle changes might help reverse MCI

Sometimes, it’s not clear to doctors what’s causing a person’s MCI. But even in these cases, there may still be a good chance of reversing it just by changing one’s lifestyle. 

For example, researchers in a 2019 study looked at a group of people with MCI where the cause was unknown and found that those who continued to stay intellectually and physically engaged—doing things like driving and using maps, reading books and newspapers, and participating in hobbies and other activities—were more likely to recover from MCI.

People who are experiencing symptoms of MCI should confer with a doctor or ask for a referral to a cognitive specialist. There might be steps they can take to restore their cognitive health.