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Millions of Americans have mild cognitive impairment and don't know it

Recent studies from USC Dornsife have raised alarms about a massive number of undiagnosed cases of mild cognitive impairment (MCI) in America. 

The research suggests that among the 8 million Americans who have mild cognitive impairment, more than 90 percent are unaware of their condition. 

Mild cognitive impairment

While many people dismiss forgetfulness as a normal sign of aging, it could be an indicator of mild cognitive impairment. 

This condition is a precursor to Alzheimer’s disease, which makes early diagnosis vital for taking preventative measures or benefiting from treatments. 

However, most cases of mild cognitive impairment remain undetected, as highlighted by two parallel studies from the USC Dornsife College of Letters, Arts, and Sciences.

Alarming findings

In the first study, published in the journal Alzheimer’s Research & Therapy, data from 40 million Medicare beneficiaries showed that less than eight percent of MCI cases had been diagnosed. This means that out of the predicted 8 million MCI cases, about 7.4 million remain undiagnosed.

“This study is meant to raise awareness of the problem,” said Soeren Mattke, director of the Brain Health Observatory at USC Dornsife’s Center for Economic and Social Research, who led the investigations. 

“We want to say, ‘Pay attention to early changes in cognition, and tell your doctor about them. Ask for an evaluation.’ We want to reach physicians to say, ‘There’s a measurable difference between aging and pathologic cognitive decline, and detecting the latter early might identify those patients who would benefit from recently approved Alzheimer’s treatments.'”   

Socioeconomic factors 

The prevalence of mild cognitive impairment is associated with socio-economic and clinical factors. Conditions like cardiovascular disease, diabetes heighten the MCI risk. 

Unfortunately, these health issues are more prevalent among members of historically disadvantaged groups, including those with less education. These groups also face poorer MCI detection rates, leading to a double jeopardy of higher risks and lower diagnoses.

Underdiagnosed cases

The second study, published in the Journal of Prevention of Alzheimer’s Disease, found that a staggering 99 percent of the 200,000 surveyed primary care clinicians underdiagnosed mild cognitive impairment. 

“There’s really just a tiny fraction of physicians in a position to diagnose MCI who would find these cases early enough for maximum therapeutic potential,” explained Mattke.  

Understanding mild cognitive impairment is crucial because it refers to cognitive functioning levels and not a disease. 

With MCI, challenges to everyday functioning tend to be more sporadic, said Soo Borson from the Keck School of Medicine. She noted that mild cognitive impairment can come in various forms, and forgetfulness is the most familiar form.

Challenges in diagnosis

Several barriers contribute to the underdiagnosis of mild cognitive impairment, including the patient’s lack of awareness and the potential for a doctor to miss the signs. Also, clinical visits often neglect brain health discussions.

Mattke believes in risk-based MCI detection. Focusing on high-risk individuals could make the diagnosis process more efficient. Detection rates may be improved by digital tests administered prior to clinical visits. 

Early treatment

Early treatment is vital, said Mattke, because the brain is limited in its ability to recover – brain cells, once lost, do not grow back, and any damage can no longer be repaired.  

“For MCI caused by Alzheimer’s disease, the earlier you treat the better your outcomes. This means even though the disease may be slowly progressing, every day counts.”  

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