People with autism have a much higher risk of developing dementia, according to a major new study.
Researchers at Drexel University in Philadelphia, Pennsylvania, linked this rapidly growing disease to a four- to eight-fold increased risk of the memory-robbing disorder compared to the general population.
The authors reviewed two studies: A 2019 study on ASD and dementia among autistic adults enrolled in Medicare and a 2021 study on the incidence of early-onset dementia among adults with ASD enrolled in Medicaid.
They analyzed data from 114,600 people aged 30 or older between 2008 and 2017 who had a diagnosis of ASD and ASD plus another intellectual disability (ID).
About one in 36 American children and one in 45 adults have autism, according to the CDC (although that number is growing rapidly), and previous research has revealed a “known association between intellectual disability (ID) and dementia.”
Overall, the review found that dementia diagnoses were present in eight percent of people who had previously been diagnosed with ASD and in almost nine percent of people who had ASD plus another ID.
In 2022, four percent of all adults aged 65 and older had ever received a diagnosis of dementia, with Alzheimer’s. The disease is the most common form of dementia, diagnosed in nearly 7 million Americans.
2025 review It also found that the odds of a dementia diagnosis increased with age.
Among people age 65 and older, 35 percent of people in the ASD-only group and 31 percent of people in the ASD plus another ID group had dementia.
The researchers acknowledged that a limitation of their study was that the data spanned a wide period of time and said more research was needed.
Furthermore, they wrote: ‘Our data highlight the importance of health policy efforts for the growing ASD population at risk for or affected by dementia.
“Future research should address factors that could contribute to the coexistence of neurodevelopmental and neurodegenerative diseases, including barriers to accessing educational and social opportunities, as well as biological mechanisms of shared pathophysiology.”
Separately, the 2019 study found that women with autism were 8.5 times more likely to have some type of cognitive condition, including dementia, compared to women without ASD.
Men with this condition were also 8.2 percent more likely to have a cognitive disorder, which also included delirium, amnesia and “other” cognitive conditions.
However, those researchers acknowledged that other studies have found that older autistic adults are equally or less likely to experience age-related cognitive changes, saying there are discrepancies due to the methodology used and the group of people studied, who vary in age. , a major contributor. to cognitive disorders.
In the 2021 study, researchers found that the prevalence of dementia among adults with ASD alone was four percent and five percent among people with ASD and another ID, compared to one percent among people without ASD or ID.
Researchers aren’t sure why there is a link between the two conditions, but the 2021 study said there may be “possible overlap” in the factors that cause both dementia and ASD, including shared genetic mutations.
And dementia medications have been found to work to reduce cognitive and communicative functioning in adults with ASD, which could indicate a shared cause.
Also, a separate 2021 study found that several genes and proteins have been linked to both ASD and Alzheimer’s disease, and the two conditions share multiple symptoms, including insomnia, weak neuromuscular function, and dementia.
Autism diagnoses in the United States have increased over the past decade, data show, and dementia diagnoses are expected to do so as well. While 7 million Americans currently have Alzheimer’s disease, that number is expected to double by 2030.
Generally, most people with ASD are diagnosed at age five, although some may be tested at age two, and dementia occurs more frequently in older people.
A recent analysis of millions of medical records found that among all age groups, autism diagnoses increased 175 percent between 2011 and 2022, from a rate of 2.3 to 6.3 per 1,000 people.
The largest increase was among young adults aged 26 to 34, with a 450 per cent increase, although children aged five to eight remain the group most likely to be diagnosed, at a rate of 30 per 1,000.
While experts don’t know what causes the condition, recent research suggests that environmental factors such as pollution, illness during pregnancy, and older parental age could be to blame.
Better screening, greater awareness and broader diagnostic criteria could also be driving the rise in autism.
Neither condition has a cure, but medications, procedures and therapies are available to manage symptoms.