Getting Brain Health Tests if ADHD Runs in the Family

Attention-Deficit/Hyperactivity Disorder (ADHD) is a very common neurodevelopmental disorder diagnosed in childhood. Typical signs include:

• Difficulty focusing
• Difficulty controlling impulsive behaviors
• Being overly active

Although ADHD can span into adulthood, it was largely considered a childhood issue until a few years ago. 

ADHD In Adults

Currently, only about three percent of adults worldwide live with ADHD, but the prevalence and incidence rates of adults diagnosed with ADHD are increasing, according to a study published in JAMA Network Open. There’s also been an uptick in the number of studies on ADHD and adults — including ones that looked at the connection between ADHD and dementia, often yielding conflicting results. 

ADHD and Dementia

One such study, conducted by researchers from the Karolinska Institutet (Sweden), looked at ties between ADHD and dementia across generations. In other words, parents and grandparents of those with ADHD are at a higher risk for dementia than parents and grandparents of individuals without ADHD, according to a large-scale Swedish study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

Researchers looked at more than two million people born in Sweden between 1980 and 2001. Around 3.2 percent of them had ADHD. Researchers combed through national registries to link study participants to more than five million biological relatives, including parents, grandparents and uncles and aunts. Researchers follow up with these relatives to determine if they developed dementia and to what extent. Researchers found:

• Parents of study participants with ADHD had 34 percent higher risk of dementia compared to parents of participants without ADHD. 
• Risk for Alzheimer’s disease was 55 percent higher in parents of participants with ADHD. 
• Individuals with ADHD were more likely to have parents with early-onset dementia than late-onset.
• Second degree relatives such as grandparents, aunts and uncles had a lower risk for dementia than parents; grandparents of study participants with ADHD had a 10 percent higher risk for dementia than grandparents of study participants who did not. 

Researchers attribute the results to few possible theories. Family members may have the same gene variants that contribute to both conditions. Or they’re exposed to environmental risk factors. ADHD may also lead to physical conditions that raise the risk for cognitive impairment.

Does the study mean that people with ADHD have an increased risk for dementia?

That’s uncertain – the average age of dementia onset is 83. ADHD did not become a diagnosis until the 1980s, which means most people diagnosed as children haven’t reached an age where dementia symptoms are likely to show.

“The results from this study don’t provide much of an explanation, but they do concur with previously conducted studies,” says Bernard Kaminetsky, medical director, MDVIP. 

ADHA Mental Health Connections

A Taiwanese study, published in the Journal of Attention Disorders, found a connection between ADHD and mental health conditions such as bipolar disorder and depression. Argentinian found that older adults who had ADHD symptoms as adults were more likely to develop Lewy body dementia, the second most common form of dementia after Alzheimer’s disease.

Another Taiwanese study followed 675 adults between the ages of 18 and 54 with ADHD and another 2,000 adults without ADHD for 10 years. Its data suggested that adults with ADHD were 3.4 times more likely to be diagnosed with dementia compared to those without ADHD.

“None of these studies factored for variables such as family history, education level or lifestyle behaviors, which could easily have played a role,” says Kaminetsky. “I believe more research is needed before conclusions are drawn. However, I do think if you have a history of or family member with ADHD, you should work with your primary care doctor to take steps to help you maintain your cognitive health and stay on top of brain health screenings.”