Study shows adults with ADHD are three times more likely to develop dementia

Study shows adults with ADHD are three times more likely to develop dementia

New research finds that adults with ADHD are almost three times more likely to develop dementia. The researchers were unable to prove a causal relationship, only a connection between the mental disorder and impaired cognitive function. Experts recommend people prioritize proper treatment for ADHD and follow certain lifestyle habits that contribute to healthy cognitive function, such as physical activity and appropriate blood pressure.

Adults with attention-deficit/hyperactivity disorder (ADHD) are nearly three times more likely to develop dementia than adults without ADHD, according to a new study.

The new study was published last week inJAMA network openedfollowed more than 109,000 older adults in Israel to better understand whether people with ADHD are at increased risk of dementia, including Alzheimer's disease.

The researchers noted that dementia is common in older people, but the underlying etiology is not well understood. However, some previous research suggests a link between ADHD and neurodegenerative diseases.

"We were interested in understanding how brain diseases that can affect cognitive function, including ADHD, may contribute to senile dementia," Michal Schnaider Beeri, PhD, director of the Herbert and Jacqueline Krieger Klein Alzheimer's Research Center, a member of the Brain Health Institute at Rutgers University and co-author of the study, saidHealth.

“Understanding such relationships can help us focus prevention strategies on high-risk populations and shed light on new mechanisms linking these two diseases,” she said.

Dementia is not a specific disease, but a group of symptoms characterized by dysfunction in daily life due to cognitive impairment.

Dementia is considered a leading cause of disability and mortality. By 2023, an estimated 6.7 million adults age 65 or older in the United States will have this disease. This number is expected to rise to 13.8 million by 2060.

Although ADHD is generally defined as a neurodevelopmental disorder, symptoms can include: lack of attention to detail, interrupting or intrusiveness with others, and the inability to calmly engage in leisure activities.

Beeri explained that people with ADHD, especially if untreated or not treated properly, may have problems with impulse control, which can lead to unhealthy lifestyle choices.

“These can include poor dietary habits and lack of exercise, obesity and high blood pressure, all of which contribute to the risk of dementia,” she said. “Furthermore, it is conceivable that the neurobiology of ADHD contributes to impaired brain and cognitive reserve and increases dementia.” Risk in old age.”

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How women experience ADHD and its symptoms

Connecting dementia and ADHD

To better understand the connection between dementia and ADHD, researchers used data from a national cohort study of more than 109,000 people born between 1933 and 1952 and followed from 2003 to 2020.

None of the participants were diagnosed with ADHD or dementia at baseline; about half were male and the other half were female.

Researchers found that adults with ADHD had a 2.77-fold increased risk of developing dementia, even when other risk factors for dementia, such as cardiovascular disease, were present.

During follow-up, 730 participants (0.7%) received a diagnosis of adult ADHD and over 7,700 (7%) received a diagnosis of dementia. Dementia occurred in 13% of adults with ADHD and 7% without ADHD in adulthood.

However, researchers couldn't figure out why adult ADHD and dementia appear to be linked.

“The exact causes of the association between adult ADHD and dementia are unknown,” said Sven Sandin, PhD, associate professor of psychiatry at the Icahn School of Medicine at Mount Sinai and co-author of the studyHealth.

"It is possible that some of the genetic causes of ADHD and the genetic causes of dementia are the same and therefore there are similar genetic pathways for both disorders," he said.

Other studies have shown similar results.

A 2022 study found that people with ADHD have a higher risk of dementia and mild cognitive impairment. However, this risk decreased when the results were adjusted for psychiatric disorders such as depression, anxiety, substance use disorders and bipolar disorder.

And a 2023 study found that ADHD is a less common but possible cause of some cases of cognitive impairment, such as dementia.

How Childhood Affects Adult ADHD

While childhood ADHD and adult ADHD are inextricably linked, there are often experiential differences depending on when someone is diagnosed with ADHD.

Previous research has shown that 5% of children with ADHD meet ADHD criteria in adulthood, accounting for 3% of all adult ADHD cases.

Studies have also shown that ADHD has different social, psychological and genetic profiles in children and adults, and little is still known about ADHD in adults.

So are there differences in risk depending on whether someone is diagnosed in childhood or as an adult?

“We don’t know,” Beeri said. "Theoretically, ADHD is a chronic condition that begins in childhood and continues into adulthood. Therefore, we can assume that those diagnosed with ADHD in adulthood were likely to have been affected by it throughout their lives."

She noted that, on the other hand, some features differ, suggesting that childhood and adult ADHD could be considered separate disorders.

However, the researchers realized that for this particular study, they lacked information about the occurrence of ADHD in children and their exact symptoms.

“In addition, our study found an association between adult ADHD and dementia,” Sandin said. "However, future studies are needed to examine the causal pathway in more detail. For example, the associations could be due to unknown confounding factors - genetic or environmental."

How patients can prioritize future cognitive functions

Beeri emphasized that her results do not prove that ADHD causes dementia, just that there appears to be a connection.

“Based on our results, we can only conclude that there is a link between ADHD and dementia,” she said. “There is little evidence of a reverse causal relationship to suggest that if there is a biological link, ADHD could lead to dementia rather than the other way around.”

She added that it's important to note that the link between ADHD and dementia becomes weaker when medications are taken into account.

This could suggest that people treated with medication may not be at increased risk of dementia. Alternatively, it could indicate that the people being medicated are genuine ADHD patients with severe symptoms.

“Further research is needed to investigate possible shared biological mechanisms between ADHD and dementia,” Beeri said. “In addition, clinical trials are needed to examine whether psychostimulants can reduce the risk of dementia in older adults with a history of ADHD.”

The study also found that ADHD may be associated with an increased risk of dementia in adults based on general health outcomes that include modifiable risk factors such as depression, high blood pressure in midlife and smoking.

“In addition to ADHD in adults, diabetes, high blood pressure and lack of exercise also increase the risk of dementia,” Sandin said. “In the context of these many risk factors, one should try to maintain both good general health and good cognitive health.”

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