In a new study from the Mayo Clinic, researchers found that up to 5% of all cases are among people under 65 years old.
They looked at 95 international studies and estimated that nearly 4 million people worldwide are living with young-onset dementia—cases that strike between the ages of 30 and 64.
In the United States, an estimated 175,000 people have the condition, accounting for roughly 3% of all dementia cases nationwide.
It’s important for people, including doctors, to be aware that dementia can arise unusually early in life. Because young-onset dementia is so uncommon, most doctors have little or no experience in diagnosing it.
And since dementia is typically associated with aging, it’s natural to attribute younger people’s memory issues to conditions that are far more common in their age group, like depression or anxiety.
The researchers suggest that some red flags include symptoms that are “pervasive” and worsen over time. In addition, cognitive complaints that go beyond memory lapses are important.
“Cognitive” symptoms include an array of problems related to thinking, reasoning, judgment and learning.
In the study, the team analyzed dozens of previously published studies, and they estimated there are 119 cases of young-onset dementia per 100,000 people worldwide. That translates to 3.9 million people living with the disease.
Based on the global prevalence of dementia, the young-onset form may account for about 5% of all cases.
They found dementia was exceedingly rare among the youngest adults, at roughly 1 case per 100,000 among 30- to 34-year-olds. People in their early 60s had the highest prevalence—about 77 cases per 100,000.
Unfortunately, people with young-onset dementia typically go for years without a diagnosis.
The team says that the first symptoms in young people are usually not the symptoms you would expect when you think of dementia.
Instead of memory impairment, young people more often present with changes in behavior or emotions, or sometimes language problems.
As for the causes of early dementia, they include the same culprits seen in late-onset—namely, Alzheimer’s disease and vascular conditions, like stroke, that impair blood flow to the brain.
But another rare type of dementia, frontotemporal dementia, is most often diagnosed at a younger age. That disease is inherited in about one-third of cases, according to the Alzheimer’s Association.
If you care about dementia, please read studies about this common health problem may increase your dementia risk and findings of your neighborhood may affect your dementia risk.
For more information about dementia and your health, please see recent studies about fighting dementia with play: Cognitive training may improve brain function and results showing that lack of this vitamin may lead to dementia.
The study is published in JAMA Neurology. One author of the study is Dr. David Knopman.
Copyright © 2021 Knowridge Science Report. All rights reserved.
