ADHD and Dementia: A Connection Worth Noticing?

Scientific understanding of the brain mechanisms behind ADHD (Attention Deficit Hyperactivity Disorder) is still in its early stages. Many common elements linked to diagnosis remain undocumented and untreated. Although structural and functional abnormalities in the Central Nervous System (CNS) are often linked to ADHD, there is a paucity of reliable neurobiological explanations. However, a futher complexitity is appearing more frequently in peer reviewed literature. Neuropsychologists are starting to talk about a glaring gap in our understanding: a possible link between ADHD and dementia.

A broader awareness of ADHD in society is starting to emerge. Current tropes often focus on energetic children, procrastination, scattered thoughts, and difficulty focusing. Dementia, by contrast, brings to mind ageing, memory loss, and cognitive decline. At first, these conditions seem incongruent: one rooted in neurodevelopment, the other in neurodegeneration. But emerging research suggests they may be more connected than we think.

In research communities, there is a growing awareness that people with ADHD are more likely to suffer dementia in later life, perhaps five to ten times more likely. The preliminary evidence suggests that individuals with ADHD may be at an increased risk of developing dementia later in life, particularly from Alzheimer’s Disease or Lewy Body Disease (LBD). This insight challenges long-held assumptions and opens up new conversations about how we understand brain health across the lifespan. In addittion research into this correlation might lead to better understanding of the trajectory and treatment of ADHD and dementia.

A groundbreaking scientific study in this field in 2024 by Golimstock and others concluded that :

“This study presents evidence that adults with ADHD seeking assistance from a neurology department are independently linked to a heightened risk of LBD, dementia, and increased na-MCI characteristics. Future studies should be carried out to determine the mechanisms underlying this existing relationship and to investigate preventive measures acting on patients who present a risk profile for cognitive impairment.” 1

The evidence identified in the research came from big data, a large-scale investigation of the health records of over 100,000 people aged 50 and over. The analysis found that those with a prior diagnosis of ADHD were significantly more likely to develop dementia compared to those without ADHD. Even after adjusting for other risk factors (such as depression, cardiovascular disease, and substance use), the association remained strong.

When combined with other recent studies in the field, the claims made by Golimstock and others are far more than a statistical curiosity. The body of research points to a deeper neurobiological overlap between ADHD and dementia. Both involve disruptions in executive function, attention regulation, and working memory. Both are linked to changes in key brain regions, such as the prefrontal cortex and hippocampus.

One of several theories in the scientific literature that might explain a link, is that both these conditions present underlying vulnerabilities such as chronic inflammation, dopamine dysregulation and reduced cognitive reserve. Cognitive reserve is the brain’s ability to compensate for damage or decline. If people with ADHD start life with a lower reserve, it could make them more susceptible to cognitive deterioration in later life. However, the complexity in establishing causality and its direction are frequently major limitations in understanding how brain function and structure are (or are not) maintained. Another theory is that ADHD related behaviors, like impulsivity, poor sleep, or difficulty managing health, may indirectly increase dementia risk. For example, someone with ADHD might struggle to maintain regular exercise, nutrition, or medication routines, all of which are protective against cognitive decline.

There is a strong degree of speculation about causal fact in the scientific literature. However, as scientific understanding of the relationship between these two conditions grows, opportunities to improve prevention and treatment will likely increase.