Can a brain scan show the differences between the brain of someone with attention deficit hyperactivity disorder (ADHD) and someone without the condition? And what does a brain scan reveal about ADHD?
As clinicians see a growing population of patients, both children and adults, with ADHD, brain scans can offer invaluable information about the differences in brain structure, cognitive function, and neurotransmitter activity in the brains of those with ADHD
The extensive research that has already been done using neuroimaging technology can give healthcare providers a foundational understanding of how ADHD brains differ. Using these insights can help clinicians communicate effectively with patients, and tie in other diagnostic tools for more objective data to complement subjective feedback.
While brain scans are not a routine step in most health practices and they can’t be used on their own to diagnose ADHD, research using brain imaging is helping clinicians better understand this multifaceted disorder. This research, combined with a better understanding of other factors like gender bias and advances in neuroimaging is helping to evolve the way ADHD is assessed and diagnosed.
In this article, we’ll dive into the factors and examine what it means for clinicians and their patients.
ADHD is a neurodevelopmental condition affecting both children and adults, leading to difficulties with attention, impulsivity, and hyperactivity. As a clinician addressing ADHD, there are various symptoms you may hear expressed by patients. Because of the comorbidities of ADHD with other conditions, such as anxiety or depression, accurate diagnosis can be difficult through purely subjective means.
Although brain scans are not typically used to diagnose ADHD, they can offer objective insights into the nature of your patient’s brain.
What are the differences seen in ADHD brain scans?
Next, we’ll dive into each of these areas further so you can understand these differences, determine the best treatment plan for ADHD, and communicate what matters most to your patients.
Research shows that individuals diagnosed with ADHD have altered brain structures compared to those without ADHD.
The brain of a child with ADHD matures more slowly, and certain areas such as the prefrontal cortex, cerebellum, hippocampus and amygdala are smaller in volume than that of typically developing children.
A study on the brain anatomy of ADHD indicates that individuals with ADHD exhibit changes in the maturation of certain areas of the brain, including white matter fiber bundles, gray matter density, the middle and superior temporal gyrus, and the frontal lobes. These structural differences may contribute to the distinct behavioral and cognitive symptoms observed in individuals with ADHD.
Functional differences in ADHD brains involve increased activity in certain areas linked to hyperactivity symptoms, as well as decreased blood flow to prefrontal areas. Functional MRI, a type of brain imaging that provides a visual representation of the brain’s activity, can be used to compare the brain function of those with and without ADHD.
These functional differences can be measured in multiple ways. Through neuroimaging, clinicians can understand the brain regions that are overactive or underactive in individuals with ADHD.
Specifically, certain brain regions have been observed to be “hyperactive” and others “hypoactive” in individuals with ADHD in comparison to those with normal brain scans. This implies that there is a variance in the neural activity levels between individuals with ADHD and those with normal brain scans.
These scans can be paired with cognitive testing, to observe how a particular patient’s attention, memory, and focus operate during particular tasks.
Cognitive testing is revealing exciting new potential for ADHD research, diagnosis, and treatment. Protocols designed specifically for ADHD highlight specific markers that indicate differences in cognitive function.
Some cognitive tasks have been validated through brain imaging, and so to the extent that ADHD is characterized by differences in brain function, those tasks are designed to pick up on differences and deficits in people with ADHD.
For example, the SART tests sustained attention, and the differences in people with ADHD show up in markers related to their errors, omissions, reaction time variability, and slowing after errors.
Brain imaging used in combination with cognitive testing can also be used over time to maintain the health and manage symptoms of someone with ADHD, by measuring the efficacy of treatment and improvements to brain function over time.
ADHD brains display differences in neurotransmitter activity, particularly lower levels of dopamine and norepinephrine when compared to non-ADHD brains. These neurotransmitters play an essential role in fundamental skills such as motivation, decision-making, and attention.
An ADHD brain scan gives just part of the picture. Interpreting the data is another key part. And with interpretation comes social factors that can bias the expression and the diagnosis of ADHD. Top of the list of social factors that can influence ADHD diagnosis is gender bias.
Large-scale studies have observed that boys tend to be diagnosed with ADHD more frequently and at a younger age than girls. The impacts of gender disparity carry consequences into adulthood, too. These statistics on gender disparity and misdiagnosis are especially poignant in light of evidence that, objectively, there’s no significant difference in ADHD symptoms between boys and girls—namely impulsivity, hyperactivity, or distractibility.
It’s important to keep in mind that social expectations and stereotypes about gender behavior may mask the symptoms of ADHD in girls. Notably, girls with ADHD may be more likely to internalize symptoms, such as anxiety, depression or inattentiveness, which can be overlooked or attributed to other causes. So being informed on these differences can also aid in accurate diagnosis.
These gender differences become increasingly complex in the context of other social intersections—including non-binary or trans gender identity, sexual orientation, race, ethnicity, and class.
With these dynamics in mind, subjective interviewing or questionnaires—while a crucial part of understanding your patient’s symptoms—may be insufficient alone to diagnose ADHD, and in fact, might reinforce gender biases. Integrating more objective measures into your practice, such as cognitive testing, can support more accurate treatment.
| Read more: Does social media have an influence on ADHD diagnosis and treatment? With more content than ever describing what it's like to live with ADHD and how to recognize symptoms, healthcare providers should be aware of the influence of social media on ADHD. |
A key difference in the ways ADHD is expressed by boys and girls shows up as hyperactivity (for boys) and inattention (for girls). In other words, the symptoms most recognized in boys are related to hyperactivity and physical activity; the symptoms most recognized in girls linked to ADHD is inattention and difficulty focusing. Because girls often face social pressure to internalize and find coping strategies for these challenges, misdiagnosis or late diagnosis is common.
Recognizing the differential presentation of ADHD in girls and boys enables healthcare providers to diagnose ADHD in girls more accurately, thus providing appropriate treatment and support.
In regards to ADHD diagnosis, brain imaging has been used to supplement clinical evaluations. Common brain imaging scans used to assess ADHD include:
Realistically, it may not be practical to refer every patient with suspected ADHD for brain imaging. These processes can be costly and time-consuming for healthcare administrators and patients alike.
But the body of research that exists today thanks to neuroimaging of ADHD brains is an excellent foundation for understanding the differences in your patient’s brain structure, function, and activity. Knowledge about these differences can help healthcare providers draw from objective data to challenge stigma and myths associated with ADHD—for example, by seeing how ADHD shows up in physical measurements, it can eliminate someone's uncertainty about whether they have it.
Today, ADHD diagnosis is often based on a combination of methods:
It’s widely recognized that brain imaging alone is insufficient for an ADHD diagnosis. But these advancements in brain imaging technology and research continue to be important to understanding the ADHD brain and developing more accurate diagnostic tools.
Neuroimaging research has formed a foundation for understanding pathophysiology in order to identify reliable biomarkers of ADHD. Understanding the neurobiology of ADHD is an area which has exciting possibilities.
In an examination of over 100 peer-reviewed papers, Creyos was able to find 14 scientifically-supported markers of ADHD. These markers correspond to cognitive tests that can aid in the diagnosis, measurement, and treatment of ADHD.
Read More: ADHD Assessment by Creyos: A Clinical Protocol and Report
A holistic view is needed to provide meaningful guidance to clinical practice. Built on neuroimaging research, cognitive testing offers a solution that is not as costly or time-consuming as referring a patient for brain scans while providing objective insights quickly and reliably.
Together, these tools provide the full picture of how brain structure, cognitive function, and neurotransmitter activity interact with possible social, behavioral, and genetic causes of ADHD. These developments will help in the creation of even more accurate diagnostic tools and targeted interventions in the future.
Fortunately, there’s substantial research on the treatment options for ADHD. The treatment of ADHD generally includes one or a combination of these categories:
Medication, specifically stimulants, are the most studied treatment for ADHD and have proven effective at managing symptoms. It’s important to note that with any ADHD treatment, when medication or lifestyle changes are discontinued, symptoms often resurface.
Combining medication with lifestyle adjustments have been shown to enhance symptom management and quality of life in individuals with ADHD.
Stimulant medications are shown to have beneficial effects for approximately 75%–90% of children with ADHD. The most common stimulant medications used for ADHD are:
ADHD medications primarily work by enhancing dopamine transmission in the brain. They’re also known to show benefits including:
Stimulant medications can also have potential side effects that have been widely reported and measured. These side effects may include:
Accurate diagnosis and appropriate treatment for ADHD are critical. Healthcare providers must be vigilant about overprescription or misuse of stimulants among young people, keeping in mind these possible adverse effects.
Lifestyle changes can play an important role in improving cognitive function and managing ADHD symptoms. Developing healthy habits and coping skills can help individuals with ADHD manage their symptoms more effectively and improve their overall quality of life.
Some lifestyle changes that can improve ADHD symptoms include:
Research suggests that regular exercise may improve focus, decrease impulsivity, and manage stress in individuals with ADHD.
People with ADHD often experience sleep disturbances, such as irregular circadian rhythm patterns. Some researchers have questioned whether stimulant medications impact sleep cycles, even as they reduce the symptoms of ADHD. For these reasons, it is important to support patients with protocols that can improve sleep, either through behavioral changes or medication adjustments.
Adopting these lifestyle modifications can facilitate better symptom management and a more fulfilling life for individuals with ADHD.
Brain scans are being used in ADHD research to improve our understanding of the causes, effective treatment options, and generally the differences between ADHD brains and normal brains.
As you treat patients, it’s essential to recognize that ADHD is a complex neurodevelopmental disorder with diverse symptoms and manifestations. Understanding the unique aspects of ADHD brains can help you more accurately diagnose and treat it.
When communicating with patients, you may encounter some questions. Below we offer suggestions for how to respond to the most frequently asked questions about ADHD diagnosis and brain scans.
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Explore these ADHD Assessments and Questionnaires available in Creyos |
This post was edited by Mike Battista, Director of Science and Research at Creyos (formerly Cambridge Brain Sciences).