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Is There a Link Between ADHD and Dementia

It’s common to have moments where we may feel our brain isn’t as focused as we would like it to be. Attention-deficit/hyperactivity disorder (ADHD) was first formally recognized as a medical condition in the late 20th century.  In 1980, ADHD was officially recognized as a mental health disorder. Since then, our understanding of ADHD has continued to evolve, with ongoing research contributing to advancements in diagnosis, treatment, and support for individuals with the condition.

According to the Centers for Disease Control (CDC), some of the more prevalent symptoms of ADHD observed among children include difficulty staying focused, frequent daydreaming, forgetfulness, squirming and fidgeting, excessive talking and requiring constant stimulation. Among adults, however, ADHD may present as restlessness or agitation.

The Centre for ADHD Awareness in Canada (CADDAC) estimates that approximately 1.8 million Canadians have ADHD affecting 4-6% of the adult population and 5-7% of children. More importantly, according to CADDAC, “ADHD remains under-recognized, underdiagnosed and misdiagnosed in Canada.” This is especially relevant considering recent studies indicating that ADHD may pose a risk factor for the development of dementia.

ADHD as a Risk Factor to Developing Dementia

ADHD is a neurodevelopmental disorder that usually starts in childhood; while dementia is a progressive neurodegenerative disorder that usually manifests much later in life and worsens over time.

In a prospective national cohort study involving 109,218 participants, individuals with and without a diagnosis of ADHD were followed up for an average of 17.2 years to observe onset of dementia. Their findings published in the Journal of the American Medical Association (JAMA) in October 2023, reported that “the presence of adult ADHD was statistically significantly associated with an increased risk of dementia.” Specifically, their study showed a 2.77-fold risk of an incident of dementia among those with an adult ADHD diagnosis compared to those without an ADHD diagnosis.

Possible Mechanism for the Increased Risk of Dementia Among Individuals with ADHD

The same study theorized that the risk for developing dementia later in life among those with a diagnosis of ADHD was related to the impact on “brain reserves;” that is, individuals with ADHD are more impaired or less able to compensate for the neurodegenerative and cerebrovascular effects that may occur later in life. Moreover, there is a strong likelihood that untreated chronic ADHD could also have an adverse effect on the prognosis of dementia.

However, when comparing the risk for developing dementia between individuals with treated ADHD and untreated ADHD, the results were inconclusive. The investigators believe that one possible explanation was that individuals requiring treatment for their ADHD were more likely to have more severe symptoms compared to those who did not receive treatment. Nevertheless, what is relevant for healthcare providers and policy makers alike is that there is sufficient evidence to pursue further investigation to determine whether ADHD is a modifiable risk factor for dementia.

The Importance of Investing in Dementia Research and Relevance of Modifiable Risk Factors

Alzheimer’s Society of Canada estimates that by 2030, approximately 1 million Canadians will be living with dementia; yet, approximately a significant 40% of dementia cases are caused by modifiable factors (e.g., high blood pressure, diabetes, depression, smoking, lack of physical activity, and alcohol consumption, to name a few).

Investing in dementia research, especially focusing on identifying modifiable factors, has the potential to improve lives and mitigate the strain in the healthcare system, its economic impact and the emotional toll experienced by families affected by dementia. By prioritizing research efforts and focusing on modifiable risk factors, we can advance our understanding of dementia, develop effective interventions, and alleviate its human and economic toll.

Karen Tyrell CPCA, CDCP is a Dementia Consultant, Educator, Author & Advocate, and Founder of Personalized Dementia Solutions Inc. ( Karen offers her expertise on dementia care through speaking engagements; workshops; support groups (both online and in-person) and by working one-on-one with families/caregivers to provide emotional support and practical solutions.  She was also on the design team for The Village Langley (Verve Senior Living) and provides ongoing education to the Village team, families and the community. If you would like to learn more, please feel free to reach out.


The contents of this blog are provided for information purposes only. They are not intended to replace clinical diagnosis or medical advice from a health professional.