Over 7 Million Americans Unaware They Have Mild Cognitive Impairment

Recent research suggests that over seven million Americans might be living with mild cognitive impairment (MCI), a condition primarily affecting those above 65, and is often an early indicator of Alzheimer's disease, without their awareness.

According to two distinct research studies conducted by the University of Southern California Dornsife College of Letters, Arts, and Sciences, MCI is an issue not frequently addressed in clinical environments.

This lack of addressing is detrimental as prompt intervention is usually necessary, states Soeren Mattke, MD, DSc, director of the Centre for Improving Chronic Illness and Care at USC Dornsife and also an author on both studies. Not addressing early-stage cognitive impairment may result in lost time and potential for early interventions.

One of the main reasons MCI remains undiagnosed is due to its multi-causal nature. According to Saket Saxena, MD, a geriatrician at Cleveland Clinic, MCI is an umbrella term for a cluster of symptoms, resulting from various possible causes, making it difficult to diagnose.

Experts provide further insights into what MCI entails, reasons it's often overlooked by doctors and what potential treatments could look like.

The first of these studies, published in Alzheimer’s Research & Therapy, utilized data from 40 million individuals aged 65 or older with Medicare insurance from 2015 to 2019. Researchers analyzed data from the Health and Retirement Study (HRS) to determine the estimated number of people with MCI numbers.

Upon comparing these estimates to the actual number of Medicare beneficiaries diagnosed with MCI, researchers found the condition was not diagnosed nearly as frequently as it should have been. Although rates of MCI detection rose minimally from 2015 to 2019, only about 8% of potential cases were diagnosed, leaving an estimated 7.4 million cases undiagnosed.

In the second study, published in The Journal of Prevention of Alzheimer’s Disease, relied on data from 226,756 primary care unit physicians and 54,597 doctor's offices. Only clinicians or practices with a minimum of 25 patients aged 65 or older and enrolled in Medicare insurance were included in the research.

The experts discovered that around 99% of clinicians underdiagnosed MCI. Researchers expressed surprise at the extent of this gap in diagnosis.

Dr. Saxena describes MCI as a condition whose symptoms overlap with Alzheimer’s and dementia. The standout factor being how severely these symptoms disrupt the individual's daily life.

Diagnose of MCI include difficulty remembering words, forgetting key events, and frequently misplacing items, which are more acute than normal aging symptoms, yet not as severe as Alzheimer's symptoms.

Approximately 10 to 20% of individuals over 65 likely suffer from MCI, which increases with age. MCI can be caused by various factors, including adverse medication reactions or excessive alcohol use. Other potential causes range from depression, increased stress levels, social isolation, and chronic conditions like heart failure or obstructive sleep apnea.

Treatment for MCI generally depends on the cause of the symptoms, for instance, if the symptoms are due to depression or a new medication, appropriate treatment may resolve the issue.

But early detection of MCI is important because, in some cases, the underlying causes can be treated better when caught early. “The earlier you treat Alzheimer’s disease, the better,” said Mattke. Most drugs for Alzheimer’s work better in people who aren’t in the advanced stages of the disease.

The vagueness with which MCI is defined is one of the reasons it goes undiagnosed so often. The fact that the symptoms aren’t as drastic as those of Alzheimer’s also contributes to the low detection rates.

“[MCI] is a pretty broadly defined category of memory problems,” said Mattke. “The symptoms are not severe, and since they occur mostly in elderly people, they often get discounted as just getting older. People think, ‘That’s just the way it is.’”

Older people often simply adapt to memory issues, rather than bringing them up to their provider, he added. “They find a way to adjust to it,” said Mattke. “[For instance,] they may just stop driving at night because orientation is harder when it’s dark.”

People should not wait to see a doctor if they’re experiencing memory trouble, said Saxena, explaining that any symptom of MCI—no matter how small it may seem—is a good reason to get evaluated.

If a doctor brushes off worrisome symptoms as normal signs of aging, it may be helpful to see an expert, such as a geriatrician, neurologist, or neuropsychologist.

Given that the symptoms are often non-specific or aren’t particularly alarming, doctors may be more inclined to watch patients with MCI symptoms rather than diagnose them with something immediately. “Many physicians don’t take early memory problems seriously,” said Mattke. “When patients do bring them up, they’ll say, ‘Come see me again in a year and we’ll see what’s happening’” if your symptoms persist.

But for MCI detection rates to improve, doctors need to be more mindful of what may be causing a person’s memory problems, and understand that they may not be age-related, Mattke added.

Ultimately, doctors need to consider the whole picture when determining what may be causing memory trouble. “Mild cognitive impairment should be approached with a broader lens,” said Saxena. “A person’s overall [well-being]—looking at their mood, mobility, social stress, making sure their blood tests are checked—all of these things need to be looked into so that we can do better by our patients.”