Table of ContentsView AllTable of ContentsADHD Brain DifferencesBrain StructureBrain FunctionBrain ChemistryHow Is ADHD Diagnosed?
Table of ContentsView All
View All
Table of Contents
ADHD Brain Differences
Brain Structure
Brain Function
Brain Chemistry
How Is ADHD Diagnosed?
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Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder. This means there are differences in the ADHD brain that affect a child’s development.ADHDdoes not influence intelligence. It does, however, affect a person’s ability to regulate attention and emotions, and it results in hyperactivity and impulsivity as well as organization problems.
While it is classified as a condition, more recent thinking views it as a form ofneurodiversity. People with ADHD brain’s process information differently, but that represents a normal variation rather than a disorder that needs to be ‘cured.’ This neurodiversity perspective emphasizes recognizing these differences and valuing strengths instead of focusing solely on challenges or deficits.
Rather than trying to change ADHD traits to fit into a neurotypical world, this perspective stresses the importance of accommodations and support to help people thrive.
At a GlanceThere are important differences between ADHD brains vs. non-ADHD brains. These differences—including those related to brain structure, function, and chemistry—explain many ADHD traits, such as inattention, hyperactivity, and impulsivity. While such traits create challenges that often require extra support, it’s important to remember that these differences are considered variations, not deficits. Understanding these unique characteristics (and what causes them) can help you better advocate for the accommodations and resources you or your child might need to succeed in different settings and situations.
At a Glance
There are important differences between ADHD brains vs. non-ADHD brains. These differences—including those related to brain structure, function, and chemistry—explain many ADHD traits, such as inattention, hyperactivity, and impulsivity. While such traits create challenges that often require extra support, it’s important to remember that these differences are considered variations, not deficits. Understanding these unique characteristics (and what causes them) can help you better advocate for the accommodations and resources you or your child might need to succeed in different settings and situations.
Differences in the ADHD Brain
ADHD has come under a lot of scrutiny over the past few decades, contributing to public misperceptions andstigma. In the past, some naysayers questioned if it was real or said a lack ofmotivation, willpower, or bad parenting caused it. Then, there was the explosion of stories suggesting that ADHD was overdiagnosed and overmedicated.
Knowing that there are biological differences in the ADHD brain—compared to the brain of a person who does not have ADHD—can be validating for someone dealing with the condition, as it provides additional evidence of the realities of ADHD.
The differences can be divided into three areas: structure, function, and chemistry.
2:33Watch Now: Strategies for Living Well With ADHD
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Watch Now: Strategies for Living Well With ADHD
ADHD vs. Non-ADHD Brain Structure
For many years, research showed there were clear structural differences in the ADHD brain. The largest review ever of ADHD patient brain scans was carried out at Radboud University Nijmegen Medical Centre and published in 2018.
Researchers reported that people with ADHD had smaller brain volume in five subcortical areas, and their total brain size was smaller, too. These differences were greater in children and less in adults.
Parts of the ADHD brain mature at a slower pace (approximately one to three years) and never reach the maturity of a person who does not have ADHD.
Another interesting finding was that the amygdala and hippocampus are smaller in the brains of people with ADHD. These areas are responsible foremotional processingand impulsivity and had previously not been definitively connected to ADHD.
What Is Impulsivity?
ADHD vs. Non-ADHD Brain Function
There are several types of brain imaging techniques that allow researchers to study how the ADHD brain operates and functions. These include:
There are alterations in blood flow to various areas of the brains in people with ADHD compared to people who do not have ADHD, including decreased blood flow to certain prefrontal areas.Decreased blood flow indicates decreased brain activity.
The prefrontal area of the brain houses theexecutive functions, which are responsible for many tasks, including planning, organizing, paying attention, remembering, and emotional reactions.
Evidence also suggests that ADHD may be related to dysfunctional brain connectivity. Research using resting-state MRIs suggests that individuals with ADHD may have increased functional connectivity in certain regions of the brain.
Research has found that children with ADHD do not have the same connections between the frontal cortex of the brain and the visual processing area.This suggests that the ADHD brain processes information differently than a non-ADHD brain.
ADHD vs. Non-ADHD Brain Chemistry
The brain is a busy communication network where messages are relayed from oneneuron(brain cell) to the next. There is a gap between neurons, which is called a synapse. In order for the message to be passed along, the synapse needs to be filled with a neurotransmitter.Neurotransmittersare chemical messengers, and each one is responsible for different functions.
The key neurotransmitters for ADHD aredopamineand noradrenaline. In the ADHD brain, there is dysregulation of the dopamine system.For example, there is either too little dopamine, not enough receptors for it, or the dopamine is not being used efficiently.
Stimulant medications help ADHD because they encourage more dopamine to be produced or keep dopamine in the synapses longer.
The Relationship Between Dopamine and ADHD
While PET and fMRI scans can be useful for research, they really only give an insight into how the brain is functioning at the moment the test was performed. Brain scans do not take into account how the brain operates in different situations, unlike a clinical test during a detailed interview.
In addition, the scan data that has been studied is generally based on group averages and may not apply to any particular individual. The results have not been normed, which is when large quantities of data are gathered and compared.
Takeaways
ADHD is diagnosed as a neurodevelopmental condition, but it is important to remember that it represents a normal variation in brain structure, function, and chemistry. These differences can create challenges in your life, but that doesn’t mean that they are something that needs to be “cured.” ADHD also comes with strengths.
Understanding the underlying causes of your ADHD traits can be validating–and give you a place to start when it comes to managing some of the challenges you’ll experience living in a society designed forneurotypicalbrains. Getting an accurate diagnosis is a great place to start. Depending on your unique experience, you may find that medications, therapy, ADHD coaching, accommodations, and social support can help.
ADHD Symptom Spotlight: Brain Fog
7 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Psychiatric Association (APA).Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text revision. Washington, D.C.; 2022.Schoeman R, Voges T.Attention-deficit hyperactivity disorder stigma: The silent barrier to care.S Afr J Psychiatr. 2022;28:1865. doi:10.4102/sajpsychiatry.v28i0.1865Hoogman M, Bralten J, Hibar DP, et al.Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysis.Lancet Psychiatry. 2017;4(4):310-319. doi:10.1016/S2215-0366(17)30049-4Tan YW, Liu L, Wang YF, et al.Alterations of cerebral perfusion and functional brain connectivity in medication-naïve male adults with attention-deficit/hyperactivity disorder.CNS Neurosci Ther. 2020;26(2):197-206. doi:10.1111/cns.13185Sörös P, Hoxhaj E, Borel P, et al.Hyperactivity/restlessness is associated with increased functional connectivity in adults with ADHD: a dimensional analysis of resting state fMRI.BMC Psychiatry. 2019;19(1):43. doi:10.1186/s12888-019-2031-9Wu Z, Luo Y, Gao Y, Han Y, Wu K, Li X.The role of frontal and occipital cortices in processing sustained visual attention in young adults with attention-deficit/hyperactivity disorder: A functional near-infrared spectroscopy study.Neurosci Bull. 2020;36(6):659-663. doi:10.1007/s12264-020-00492-9Véronneau-Veilleux F, Robaey P, Ursino M, Nekka F.A mechanistic model of ADHD as resulting from dopamine phasic/tonic imbalance during reinforcement learning.Front Comput Neurosci. 2022;16:849323. doi:10.3389/fncom.2022.849323
7 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Psychiatric Association (APA).Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text revision. Washington, D.C.; 2022.Schoeman R, Voges T.Attention-deficit hyperactivity disorder stigma: The silent barrier to care.S Afr J Psychiatr. 2022;28:1865. doi:10.4102/sajpsychiatry.v28i0.1865Hoogman M, Bralten J, Hibar DP, et al.Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysis.Lancet Psychiatry. 2017;4(4):310-319. doi:10.1016/S2215-0366(17)30049-4Tan YW, Liu L, Wang YF, et al.Alterations of cerebral perfusion and functional brain connectivity in medication-naïve male adults with attention-deficit/hyperactivity disorder.CNS Neurosci Ther. 2020;26(2):197-206. doi:10.1111/cns.13185Sörös P, Hoxhaj E, Borel P, et al.Hyperactivity/restlessness is associated with increased functional connectivity in adults with ADHD: a dimensional analysis of resting state fMRI.BMC Psychiatry. 2019;19(1):43. doi:10.1186/s12888-019-2031-9Wu Z, Luo Y, Gao Y, Han Y, Wu K, Li X.The role of frontal and occipital cortices in processing sustained visual attention in young adults with attention-deficit/hyperactivity disorder: A functional near-infrared spectroscopy study.Neurosci Bull. 2020;36(6):659-663. doi:10.1007/s12264-020-00492-9Véronneau-Veilleux F, Robaey P, Ursino M, Nekka F.A mechanistic model of ADHD as resulting from dopamine phasic/tonic imbalance during reinforcement learning.Front Comput Neurosci. 2022;16:849323. doi:10.3389/fncom.2022.849323
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Psychiatric Association (APA).Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text revision. Washington, D.C.; 2022.Schoeman R, Voges T.Attention-deficit hyperactivity disorder stigma: The silent barrier to care.S Afr J Psychiatr. 2022;28:1865. doi:10.4102/sajpsychiatry.v28i0.1865Hoogman M, Bralten J, Hibar DP, et al.Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysis.Lancet Psychiatry. 2017;4(4):310-319. doi:10.1016/S2215-0366(17)30049-4Tan YW, Liu L, Wang YF, et al.Alterations of cerebral perfusion and functional brain connectivity in medication-naïve male adults with attention-deficit/hyperactivity disorder.CNS Neurosci Ther. 2020;26(2):197-206. doi:10.1111/cns.13185Sörös P, Hoxhaj E, Borel P, et al.Hyperactivity/restlessness is associated with increased functional connectivity in adults with ADHD: a dimensional analysis of resting state fMRI.BMC Psychiatry. 2019;19(1):43. doi:10.1186/s12888-019-2031-9Wu Z, Luo Y, Gao Y, Han Y, Wu K, Li X.The role of frontal and occipital cortices in processing sustained visual attention in young adults with attention-deficit/hyperactivity disorder: A functional near-infrared spectroscopy study.Neurosci Bull. 2020;36(6):659-663. doi:10.1007/s12264-020-00492-9Véronneau-Veilleux F, Robaey P, Ursino M, Nekka F.A mechanistic model of ADHD as resulting from dopamine phasic/tonic imbalance during reinforcement learning.Front Comput Neurosci. 2022;16:849323. doi:10.3389/fncom.2022.849323
American Psychiatric Association (APA).Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text revision. Washington, D.C.; 2022.
Schoeman R, Voges T.Attention-deficit hyperactivity disorder stigma: The silent barrier to care.S Afr J Psychiatr. 2022;28:1865. doi:10.4102/sajpsychiatry.v28i0.1865
Hoogman M, Bralten J, Hibar DP, et al.Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysis.Lancet Psychiatry. 2017;4(4):310-319. doi:10.1016/S2215-0366(17)30049-4
Tan YW, Liu L, Wang YF, et al.Alterations of cerebral perfusion and functional brain connectivity in medication-naïve male adults with attention-deficit/hyperactivity disorder.CNS Neurosci Ther. 2020;26(2):197-206. doi:10.1111/cns.13185
Sörös P, Hoxhaj E, Borel P, et al.Hyperactivity/restlessness is associated with increased functional connectivity in adults with ADHD: a dimensional analysis of resting state fMRI.BMC Psychiatry. 2019;19(1):43. doi:10.1186/s12888-019-2031-9
Wu Z, Luo Y, Gao Y, Han Y, Wu K, Li X.The role of frontal and occipital cortices in processing sustained visual attention in young adults with attention-deficit/hyperactivity disorder: A functional near-infrared spectroscopy study.Neurosci Bull. 2020;36(6):659-663. doi:10.1007/s12264-020-00492-9
Véronneau-Veilleux F, Robaey P, Ursino M, Nekka F.A mechanistic model of ADHD as resulting from dopamine phasic/tonic imbalance during reinforcement learning.Front Comput Neurosci. 2022;16:849323. doi:10.3389/fncom.2022.849323
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