Stop Saying ADHD Isn't Real: Here's the Science
Attention-Deficit/Hyperactivity Disorder (ADHD) is a complex neurodevelopment condition that affects millions worldwide. Let's debunk the claim that ADHD isn't real.
Attention-Deficit/Hyperactivity Disorder (ADHD) is a complex neurodevelopment condition that affects millions worldwide. While often misunderstood as a purely behavioural issue, research has firmly established that ADHD has a biological basis, with measurable differences in brain structure and function.
This article explores the physical distinctions of the ADHD brain, the scientific evidence supporting its validity, and a discussion of a recent interaction that highlights the challenges in convincing skeptics.
Addressing the Skeptic: A Personal Encounter
Recently, I engaged with an individual who insisted that ADHD "isn't real." Despite presenting extensive evidence from peer-reviewed studies, they dismissed or selectively interpreted the information to fit their narrative. This interaction underscored the importance of understanding ADHD's biological foundation and recognising the role of evidence-based science in combating misinformation.
Throughout our discussion, I presented key findings about ADHD's physical and functional differences, including reduced brain volume, delayed cortical maturation, and neurotransmitter imbalances.
Unfortunately, the individual avoided addressing these points directly, instead focusing on anecdotal claims. They offered no evidence to support their assertion, highlighting the common pattern of denial rooted in opinion rather than fact.
My Personal Experience with ADHD
As someone who has lived with severe ADHD since childhood, I’ve experienced firsthand the challenges it presents. Throughout school, I struggled to keep up with peers. I was often labeled as lazy or inattentive, and despite my obvious potential, I never received the help I desperately needed.
Like so many with ADHD, I experienced the archetypal frustrations: unfinished homework, difficulty following instructions, and a constant sense of being overwhelmed.
It wasn’t until I left school and entered college that I finally started to thrive. Hyperfocus—a lesser-known trait of ADHD—kicked in. I became obsessed with the subjects I studied and learned what I should have learned years earlier.
This same hyperfocus extended to programming, which eventually led to my career in software engineering. ADHD didn’t just hinder me; it shaped my path in unexpected ways, fuelling my curiosity and passion for problem-solving.
Sharing my story isn’t just cathartic—it’s essential to humanise the condition and dispel harmful myths. ADHD isn’t an excuse or a failing; it’s a real, tangible challenge that requires understanding and support.
The Physical Differences in the ADHD Brain
Extensive studies have identified specific physical differences in the brains of individuals with ADHD compared to neurotypical individuals:
Reduced Brain Volume:
Key areas of the brain, including the prefrontal cortex, basal ganglia, and cerebellum, tend to be smaller in individuals with ADHD. These regions are vital for executive functions like attention, impulse control, and motor regulation.
Delayed Cortical Maturation:
Research shows that individuals with ADHD experience a delay in cortical thickening, particularly in the prefrontal cortex. This delay can affect the development of skills like decision-making and self-regulation, contributing to hallmark ADHD symptoms.
Abnormal Functional Connectivity:
The neural circuits connecting different parts of the brain, such as the default mode network (DMN) and frontostriatal pathways, function differently in ADHD brains. These disruptions impact the ability to switch focus, regulate attention, and control impulses.
Dopamine Dysregulation:
Dopamine, a neurotransmitter crucial for motivation, reward processing, and attention, is less active in ADHD brains. This under-activity contributes to difficulties in sustaining focus and regulating behaviour.
These findings collectively highlight that ADHD is deeply rooted in the brain’s biology, challenging misconceptions that it is simply the result of poor parenting or lack of discipline.
Why Does the ADHD Brain Work Differently?
Understanding why these differences occur involves examining a combination of genetic, neurochemical, and environmental factors.
Genetic Influences:
ADHD is highly heritable, with studies suggesting a genetic contribution of up to 76%. Variations in genes related to dopamine regulation, such as DRD4 and DAT1, are commonly associated with ADHD. These genetic factors affect how dopamine is processed, influencing reward sensitivity and attention.
Neurotransmitter Dysregulation:
ADHD is closely linked to imbalances in dopamine and norepinephrine systems. These neurotransmitters regulate focus, impulse control, and emotional responses. Reduced dopamine activity in areas like the prefrontal cortex and striatum explains many of the core symptoms of ADHD.
Delayed Neurodevelopment:
ADHD brains develop more slowly, particularly in regions responsible for executive functions. Cortical development in individuals with ADHD is delayed by an average of 2-3 years, leading to challenges in areas like organisation, planning, and impulse control.
Environmental Contributions:
Certain environmental factors during pregnancy and early childhood can increase the risk of developing ADHD:
Prenatal exposure to smoking, alcohol, or stress.
Low birth weight or premature birth.
Childhood exposure to toxins like lead.
While these factors do not directly cause ADHD, they can influence brain development and exacerbate symptoms.
Brain Network Disruptions:
Functional imaging studies reveal disrupted communication between key brain networks in ADHD, including:
The default mode network (DMN), which is overactive and disrupts focus on tasks.
The executive network, which is under-active and struggles to maintain attention and regulate behaviour.
A Skeptic’s Approach: Ignoring the Evidence
Despite presenting this wealth of information, the skeptic chose to focus on select portions of the data while ignoring the larger context. For example, they dismissed findings on dopamine dysregulation, claiming it was unrelated to ADHD, yet failed to provide alternative explanations for the overwhelming scientific consensus.
This pattern—cherry-picking evidence and failing to engage with biological factors—is a common issue in ADHD denial. It emphasises the need for broader education about the condition and the importance of relying on peer-reviewed science rather than personal opinions.
An Evolutionary Perspective
Some researchers suggest that ADHD traits may have been advantageous in certain historical contexts. Impulsivity, hyperfocus, and novelty-seeking behaviours could have benefited hunter-gatherer societies, where quick decision-making and adaptability were crucial. This evolutionary perspective offers insight into why ADHD persists as a heritable trait in modern populations.
A Broader Understanding
ADHD is not a character flaw or a result of poor upbringing. It is a neurodevelopment condition with clear physical and functional differences in the brain. Understanding these differences—and their potential causes—is essential for reducing stigma and promoting effective treatment strategies.
By acknowledging the biological roots of ADHD, we can better support individuals living with the condition, fostering environments where they can thrive. Continued research will undoubtedly shed even more light on the complex interplay of factors shaping the ADHD brain, paving the way for improved interventions and greater acceptance.
Finally, if you’d like watch Charles Walker talk about ADHD, where he goes into ADHD.