ADHD and dementia: Is there a link?

If you have ADHD, it’s common to forget appointments, get distracted, or lose your train of thought due to challenges with executive function. As you get older, though, you might wonder — what’s the difference between ADHD forgetfulness and dementia? 

That’s a question researchers have been trying to understand. A 2026 study in JAMA Psychiatryopens in a new tab by researchers at the University of Pittsburgh found that adults with ADHD had about four times the riskopens in a new tab of developing dementia or mild cognitive impairment over time, compared to adults without ADHD. 

We’ll break down what else the research found, how to tell ADHD forgetfulness from age-related cognitive changes, and what you can do now to support your brain health later. 

Researchers at the University of Pittsburgh followed more than 187,000 adults ages 50 and up for about 10 years. When they looked at dementia on its own — without other kinds of cognitive decline — they found that people with ADHD had about three times the risk. 

They also looked at people’s genes. Those with the highest genetic risk for ADHD were 35 percent more likely to develop cognitive impairment.

The research doesn’t mean ADHD causes dementia or cognitive decline. It just shows a link. Most of the participants with ADHD didn’t develop either condition during the course of the study. After adjusting for things like age and other health conditions, about 7 in 100 people with ADHD developed either cognitive decline or dementia. Without ADHD, it was about 3 in 100 people.

This study is just one of many research studiesopens in a new tab that have explored the relationship between ADHD and dementia.opens in a new tab But more research is needed to investigate the link, says Douglas Teixeira Leffa, MD, PhD, one of the study’s authors. 

“We need long-term studies that follow people with well-characterized ADHD across adulthood and into older age, ideally with repeated cognitive assessments, biomarkers, and information about treatment and other health and lifestyle factors,” he says. “This would help determine whether ADHD itself contributes to [dementia] risk, and whether the association is driven by shared biological or environmental factors.” 

While researchers don’t yet know why ADHD and dementia are connected, there are a few theories of what’s behind the link. 

ADHD is associated with cognitive differences in attention and challenges with executive function. This may mean that people with ADHD have less “cushion” than others before cognitive impairments are noticeable. For example, you may notice that it’s harder than usual to remember where things are in the house or plans you’ve made for the week. 

Researchers found that people with the highest genetic risk scores for ADHD were more likely to develop cognitive impairment later in life, compared to people with the lowest scores. This may mean ADHD and age-related cognitive decline share some genetic roots, but researchers are still working to understand how. 

If you have ADHD, you have an increased risk for some other health conditions, such as:

• Sleep disorders (i.e., insomnia and sleep apnea) 

• Heart disease

• Obesityopens in a new tab

• Depressionopens in a new tab

• PTSDopens in a new tab

These conditions independently increase your risk of cognitive impairment and dementia. That’s why researchers think that having ADHD — and these other conditions — compounds your risk of cognitive impairmentopens in a new tab as you get older. 

If you have ADHD and have trouble with impulsivity, you may be more likely to use tobacco productsopens in a new tab or have substance use disorder.opens in a new tab These behaviors also raise your risk of cognitive impairment with age. 

It can be hard to tell the difference between ADHD and other cognitive changes. But it’s important to keep in mind when your symptoms started, says Brandy Callahan, PhD,opens in a new tab an associate professor of psychology at the University of Calgary who studies the relationship between ADHD and dementia. 

“In ADHD, cognitive and behavioral difficulties start to show in early life, and although they may change across the lifespan with certain events (e.g., get worse during menopause), they don’t get progressively worse, only fluctuate up and down,” Callahan says. “In contrast, dementia is typically a late-onset syndrome where new symptoms that have never been present before begin to manifest in later life and get progressively worse over time.” 

That said, symptoms of ADHD, cognitive impairment, dementia, and age-related memory changes can still overlap. Here’s a breakdown of the differences. 

ADHD symptoms are usually chronic and typically show up in childhood. These can include:

• Having a hard time staying on task and reorienting to the task

• Needing reminders frequently

• Having trouble staying focused on work or chores 

• Other problems associated with executive function, such as planning and initiating tasks, or regulating emotions

Some memory and thinking speed changes are a natural part of aging. These cognitive changes typically happen when someone is around 50 to 60 years old. They can include:

• Taking longer to learn something new 

• Trouble with decision-making, planning, and multitasking 

• Forgetting to do a future task 

• Occasionally missing a bill payment or meeting 

• Taking longer to recall information 

• Sometimes misplacing things

Mild cognitive impairmentopens in a new tab (MCI) refers to problems with memory or thinking that are beyond what is expected with aging. However, these problems are not as severe as dementia or Alzheimer’s disease. 

Typically, if you have MCI, the symptoms are noticeable to your family members but don’t interfere with your ability to live independently. About 12 to 18 percent of people over age 60opens in a new tab have MCI. Symptoms include:

• Difficulty with basic mental math 

• Misplacing items in the house or car 

• Challenges with using familiar items like the dishwasher, TV, or washing machine

• Trouble with word finding or using the wrong words 

• Forgetting or having a hard time recalling important phone numbers 

• Using words like “things” or “stuff” to replace other words 

Dementia is a decline in cognitive abilityopens in a new tab to the extent that it interferes with your ability to do day-to-day activities. Dementia gets worse over time, and people with dementia may not know it’s happening to them. Alzheimer’s disease is the most common form of dementia. 

Most people don’t develop dementia. Among those who do, the symptoms usually start to become noticeableopens in a new tab around 65 years old. Symptoms include:

• Symptoms of mild cognitive impairment

• Memory loss

• Challenges with managing finances, grooming, and taking medications 

• Forgetting or having trouble with common concepts 

• Trouble remembering time and place, like what day it is or where you are

• Inability to recognize family and friends 

It’s possible to experience forgetfulness as an older adult, unrelated to cognitive impairment. For example, the following can all lead to brain fog — and make your existing ADHD symptoms worse:

• Perimenopause

• Menopause

• Sleep problems

• Depressionopens in a new tab

• Medication side effectsopens in a new tab

The 2024 Lancet Commission on Dementia Prevention, Intervention, and Careopens in a new tab estimated that around 45 percent of dementia cases worldwide could potentially be prevented or delayed by addressing certain risk factors throughout life. These risk factors include: 

• Physical inactivity 

• Social isolation

• Hearing loss 

• Untreated hypertension 

• Diabetes

• Depression

• Smoking

• Excessive alcohol consumption

• Obesity 

• Elevated LDL cholesterol 

• Other environmental and health-related risks

One indirect link between ADHD and dementia is an unhealthy lifestyle. Researchopens in a new tab suggests that those with ADHD may be less likely to follow a healthy lifestyle due to challenges with consistency, self-discipline, and impulse control. 

But there are a number of things you can do to be proactive about your brain health. Consider the following tips:

It’s important to keep track of your ADHD symptoms and whether or not your treatment is still working as it should. Impulsivity can increase your risk of using tobacco, alcohol use disorder, and disordered eating. These behaviors can all raise your risk of dementia. Unmanaged inattention symptoms can also mask cognitive changes. 

Diabetes, heart disease, and obesity are linked to both ADHD and brain health. Eating a balanced diet, maintaining a healthy blood pressure, and getting regular physical activity can help prevent and manage these conditions. 

ADHD is associated with sleeping disorders, like insomnia and sleep apnea. Not getting enough sleep can make your ADHD symptoms worse and increase your risk for dementia. Work with your health care provider to address any underlying sleep disorders or problems. 

Social isolation and loneliness can increase your risk of depression and dementia. If you have ADHD, try to proactively schedule social activities to stay engaged with others.

People may think that you’re not paying attention because of your ADHD. But you may be experiencing age-related hearing loss. Hearing loss as an older adult can increase your risk for social isolation, depression, and dementia. If you’re asking others to repeat themselves more than usual or others notice an increase in inattention, you may want to consider getting a hearing test.

If you are concerned about changes in your cognitive health, talk to your health care provider. There are several tests available to help them better understand your cognitive symptoms. Be sure to bring up your ADHD history and how you’ve managed it, what changes you’ve noticed, and when those changes started. 

If you’re concerned about a loved one’s cognitive changes, consider going with them to any health care appointments — with their permission, of course. Sharing changes you’ve noticed in them can greatly help their provider tease out what’s going on. Some things to watch out for and share include:

• Memory or thinking changes that are new or getting worse

• How these changes are affecting your loved one’s daily life

• When you or others first started noticing these changes

Asking questions early is a good first step. And getting the right treatment can make a real difference. 

Thumbnail image credit: zeljkosantrac via Getty Images