Not All ADHD Is the Same: What New Brain Imaging Research May Mean for the Future of ADHD Care
A 2026 study in JAMA Psychiatry used brain imaging to sort people with ADHD into three distinct patterns, or "biotypes," based on how different brain regions relate to one another structurally. It's genuinely interesting research. It is not a new way to diagnose ADHD, and it changes nothing about how evaluation works in a clinic today.
Educational only: This article is for general education and does not replace medical advice, diagnosis, or treatment. ADHD and related conditions require individualized clinical evaluation. If you are in medical or psychiatric crisis, call 911 or go to the nearest emergency department.
Related reading: ADHD article hub, how to know if you have ADHD as an adult, executive dysfunction in ADHD, ADHD in women, rejection sensitivity and emotional dysregulation, and ADHD vs. anxiety.
If you follow ADHD news at all, headlines about "ADHD brain scans" and "biotypes" understandably grab attention. Anyone who has spent years being told ADHD is "just" inattention, or has watched a sibling with a very different presentation get the same diagnosis, has reason to wonder whether there's more going on beneath the surface. This study is a real, credible step toward answering that question at a research level.
It is also easy to overstate. So this article does two things: it explains what the study actually found, in plain language, and it draws a clear line around what has not changed—starting with the fact that a brain scan is not part of how ADHD gets diagnosed, and won't be for the foreseeable future.
What the New Study Actually Did
The study—Bu X, et al., "Mapping ADHD Heterogeneity and Biotypes by Topological Deviations in Morphometric Similarity Networks," published in JAMA Psychiatry in 2026—set out to address a long-recognized problem: ADHD is not one uniform condition. Two people can both meet full diagnostic criteria and look almost nothing alike day to day.
The researchers analyzed structural brain MRI data from a discovery cohort of 446 people with ADHD and 708 control participants without ADHD, then tested whether the patterns they found held up in a separate validation cohort. Using a data-driven statistical approach, they grouped participants with ADHD according to similarities in brain network organization, then looked at whether those groupings lined up with meaningful differences in clinical symptoms.
They did. Three subgroups emerged with reasonably distinct brain network signatures and symptom profiles—work now going through the normal scientific process of scrutiny, replication, and debate that any single study, however well-designed, has to earn before it changes practice.
What Is a "Morphometric Similarity Network"? In Plain Language
The technical term in the study's title—morphometric similarity network—sounds more intimidating than the underlying idea. Breaking down the pieces helps.
"Morphometric" simply refers to measurements of brain structure: things like cortical thickness, surface area, and the microstructural properties MRI can capture in different regions. No single one of these measurements tells you much on its own. A "similarity network" is a way of comparing many regions to each other across several of these measurements simultaneously, then mapping how similar or different each region is relative to every other region—turning the brain into a network of relationships rather than a list of isolated numbers.
Think of it less like measuring the size of ten rooms in a house, and more like mapping how similar those rooms are to each other in layout, material, and function—then asking whether that map of relationships looks different in houses built by different architects. The "architecture" being compared here is a brain's structural organization, and the "different architects" are the three biotypes the study identified. This kind of network-level analysis can pick up organizational patterns that comparing single regions in isolation would miss.
It's a legitimate and increasingly common approach in psychiatric neuroimaging research. It is still, importantly, a research tool for studying groups—not a diagnostic test applied to one person's scan in a clinical visit.
The Three ADHD Biotypes Described in the Study
Within the ADHD group, the analysis identified three biotypes, each associated with a different pattern of network alterations and a different dominant symptom profile. The table below summarizes them at a high level.
In plain terms: the medial prefrontal cortex is heavily involved in self-regulation, decision-making, and processing emotional significance; the anterior cingulate cortex plays a role in monitoring conflict, sustaining attention, and inhibiting impulses; the superior frontal gyrus contributes to attention and working memory; and the pallidum is part of the basal ganglia, a structure involved in motivation, reward processing, and motor regulation. The biotypes each pair a cortical region associated with a particular cognitive or emotional function with a subcortical structure tied to motivation and regulation—which lines up, at least descriptively, with each group's dominant symptom pattern.
The biotype most relevant to a group many clinicians already recognize clinically is the first one—severe-combined presentation with prominent emotional dysregulation. Emotional dysregulation and rejection sensitivity are already familiar territory in ADHD care even without imaging; our guide on rejection sensitivity in ADHD covers that experience from a clinical, non-imaging angle. This study offers one possible biological correlate for a pattern clinicians have long observed simply by listening to patients.
Why This May Help Explain Why ADHD Looks So Different From Person to Person
Clinicians have never treated ADHD as one uniform experience. The DSM-5-TR itself already splits presentations into predominantly inattentive, predominantly hyperactive-impulsive, and combined types, and anyone who has spent time in ADHD care knows that two people with the same "combined type" label can still look quite different—one dominated by restlessness and impulsivity, another by a quieter inattentiveness layered with intense emotional reactivity.
What this research adds is a possible biological angle on why that heterogeneity exists, rather than treating it as noise around a single "true" ADHD signature. If distinct network patterns really do track with distinct symptom clusters, that would help explain a puzzle that has bothered researchers for a long time: why a single diagnostic label captures people who don't always respond to the same interventions in the same way, and why family members with ADHD can look meaningfully different from one another.
That framing matters for a reason beyond the biology itself. Presentation-based variability is also visible outside imaging studies—ADHD in women, for instance, is frequently underdiagnosed in part because presentations skew toward internalized, inattentive patterns that don't match outdated stereotypes of hyperactivity. Research like this reinforces something clinical experience already suggested: ADHD is a spectrum of related presentations, not a single fixed picture.
Could Treatment Someday Be Matched to Brain Biotype?
This is the question behind most of the public interest in this kind of research, and it deserves an honest answer: possibly, eventually, but not soon, and not based on this study alone.
The long-term hope in psychiatric neuroscience is a shift toward precision or personalized medicine—matching a person to the treatment most likely to work for their specific underlying biology, rather than the current trial-and-error approach where a first medication or therapy choice sometimes needs adjusting based on response. If biotypes like these turn out to be reliable and clinically meaningful, they could theoretically inform which treatments are tried first, or help explain why certain approaches work well for some people with ADHD and less well for others.
That is a meaningful direction for the field to pursue. It is also, at this stage, a hypothesis generated by one study—not a validated clinical tool. Before biotype-guided treatment could become real, researchers would need to show that biotypes can be reliably identified in new, independent patients; that they actually predict treatment response, not just symptom clusters; and that assigning someone to a biotype changes clinical decisions for the better, not just academically but in outcomes that matter. None of that exists yet. Personalized, imaging-guided ADHD treatment is a future research direction, not a current clinic protocol—at Siya Health or anywhere else.
What This Research Does Not Change
Given how easily "brain scan" and "biotype" headlines get overstated, it's worth being direct about what stays exactly the same.
The most important point in that table is the first one. ADHD diagnosis today rests on a clinical evaluation: a detailed history, review of symptoms against DSM-5-TR criteria, assessment of functioning across settings such as work, school, and relationships, and often collateral information or standardized rating scales. That process hasn't changed, and this study doesn't argue that it should—the authors themselves frame their work as a step toward understanding heterogeneity within ADHD, not a replacement for how the condition is diagnosed.
Limitations of the Study Worth Knowing
Good science reports its own limitations, and it's worth naming the ones most relevant to how this research should—and shouldn't—be interpreted by patients and families.
- Pediatric-heavy samples. Much of the imaging literature this type of study draws on, and often the cohorts themselves, are weighted toward children and adolescents. Findings in developing brains don't automatically transfer to adult brains, where structure and presentation can look different.
- Replication is still needed. A single discovery-and-validation study, however well-conducted, is a strong starting point—not a settled conclusion. Biotypes like these need to be tested again in independent, more demographically diverse cohorts before the field treats them as established.
- Not built for individual classification. The statistical methods used to define these biotypes were designed to find group-level patterns across hundreds of participants. That is a fundamentally different task from reliably placing one specific person into one specific category on their own scan, which the study was not designed or validated to do.
- Symptom overlap between biotypes. Real people rarely sort into perfectly clean categories. Even within a study like this, symptom profiles associated with each biotype likely overlap more than a simple three-way split suggests.
None of this diminishes the value of the research. It does mean the responsible way to read it is as an early, promising piece of a much longer scientific process—not a finished map of "what causes your ADHD."
What Patients Should Not Do With This Information
The most useful thing a patient can do with a study like this is stay curious and stay grounded. A few things are worth actively avoiding.
Don't pursue a brain MRI to try to diagnose or "confirm" your ADHD. No clinical guideline recommends imaging for standard ADHD diagnosis, and an MRI obtained for this purpose won't tell you or a clinician which biotype you might belong to, because the classification isn't validated for individual use. It also isn't a good use of the cost, radiologic resources, or time involved.
Don't assume your symptom pattern maps neatly onto one of these three groups. These biotypes came from statistical clustering in a research dataset. Real symptom presentations are more layered than any three-category system captures, which is exactly why a full clinical evaluation—not a label from a news article—is still the right way to understand your own presentation.
Don't delay evaluation or treatment while waiting for "personalized" options. Effective, individualized ADHD care already exists today through standard evaluation and treatment planning; it doesn't require waiting years for biotype-guided protocols that don't yet exist in any clinic.
If anything, the right response to research like this is the same response that's always made sense: get a proper evaluation from a clinician who takes a detailed history, rather than trying to self-diagnose from a study designed for population-level science.
How ADHD Is Actually Diagnosed Today
It's worth spelling out what a real ADHD evaluation involves, precisely because it's so different from what a "brain biotype" headline might imply.
A structured evaluation typically includes a detailed developmental and symptom history, ideally covering childhood as well as current functioning; a review of symptoms against DSM-5-TR criteria for inattentive, hyperactive-impulsive, or combined presentation; assessment of how symptoms affect multiple areas of life—work, relationships, school, daily tasks—since ADHD requires impairment across more than one setting; consideration of other conditions that can mimic or coexist with ADHD, such as anxiety or depression, covered in our ADHD vs. anxiety comparison; and often standardized rating scales or collateral input from someone who knows the patient well. Executive functioning difficulties—covered in depth in our guide to executive dysfunction in ADHD—are usually part of that conversation too, since they're often more functionally relevant day to day than any single symptom checklist item.
None of this requires a brain scan. If you're wondering what that process looks like in practice, how to know if you have ADHD as an adult walks through it in more detail, and a free ADHD screening is a reasonable, low-stakes first step if you're not sure whether a full evaluation is worth pursuing.
What This Means for Patients
Take this research for what it is: a genuinely interesting, carefully done study that adds a biological thread to something clinicians already knew from experience—ADHD doesn't look the same in every person, and emotional dysregulation, hyperactivity, and inattention don't always travel together in equal measure.
It is not evidence that your ADHD needs to be "confirmed" by imaging, and it is not a reason to wait for some future personalized protocol before getting evaluated or treated. If your current treatment isn't working well, that's a reason to talk to your clinician about your specific symptoms and history—not to search for which biotype you might be. The path to good ADHD care today is the same as it was before this study: a structured clinical evaluation, not imaging tourism.
If treatment decisions in your case have felt like guesswork, medication strategy is one area where a knowledgeable clinician can already individualize care substantially without any imaging at all—our guide to ADHD medication options for adults covers how that individualization happens in practice today.
Frequently Asked Questions
What is an ADHD "biotype"?
A biotype is a subgroup within a broader diagnosis that shares a distinct underlying pattern—in this case, a distinct pattern of brain network organization identified through statistical analysis of imaging data. It's a research classification, not a clinical diagnosis a doctor currently assigns during an ADHD evaluation.
Does this study mean the diagnosis of ADHD has changed?
No. ADHD is still diagnosed the same way it was before this study: through a clinical history, symptom criteria from the DSM-5-TR, and evaluation of functioning across settings. This research describes patterns within people who already carry an ADHD diagnosis; it doesn't redefine how that diagnosis is made.
What is a morphometric similarity network?
It's a way of mapping how similar different brain regions are to each other across several structural features measured on an MRI scan, then studying the pattern of those similarities as a network. Researchers use it to detect organizational differences between brains that a single measurement, like regional volume alone, might miss.
What are the three ADHD brain biotypes described in the study?
A severe-combined biotype with prominent emotional dysregulation, linked to differences involving the medial prefrontal cortex and pallidum; a predominantly hyperactive-impulsive biotype linked to the anterior cingulate cortex and pallidum; and a predominantly inattentive biotype linked to the superior frontal gyrus. These were statistical groupings within the study's cohort, not categories assigned in clinical practice.
Can a brain scan diagnose ADHD?
No. There's no brain scan, including MRI, that's validated or recommended for diagnosing ADHD in routine clinical care. Imaging in this research was used to study group-level patterns in a research cohort, not to evaluate individual patients, and it isn't part of a standard ADHD workup today.
Why do people with ADHD have such different symptoms?
ADHD has always been recognized as a heterogeneous condition—presentations range from predominantly inattentive to predominantly hyperactive-impulsive to combined, often layered with emotional regulation difficulties. This new research offers one possible biological angle on why that variability exists, but clinicians have long tailored evaluation and treatment to an individual's specific symptom pattern regardless of imaging.
Does this mean treatment will be personalized to my brain scan soon?
Not in the near term. Personalized, biotype-guided treatment is a long-term research direction the authors themselves frame as requiring further validation, not a protocol available in any clinic today, including at Siya Health. Current treatment decisions are based on symptoms, history, and clinical judgment.
What are the limitations of this research?
The study's cohorts were pediatric-heavy, so findings may not generalize directly to adults. The biotypes need replication in independent, more diverse samples before they're considered reliable. And the analysis wasn't designed or validated to assign an individual patient to a subtype in a clinical setting.
Should I ask my doctor for an MRI to confirm my ADHD diagnosis?
Routine ADHD evaluation doesn't require an MRI or any brain scan, and ordering one for diagnostic confirmation isn't standard practice. Imaging may be considered separately if a clinician suspects a different neurological issue, but that's a distinct clinical decision from diagnosing ADHD itself.
Where can I learn more about how ADHD is actually diagnosed today?
ADHD is diagnosed through a structured clinical evaluation, not imaging or a single test. Our guides on how to know if you have ADHD as an adult and on ADHD evaluation and care walk through what that structured process actually involves.
Getting Help
Emerging research like this is genuinely exciting to follow, but it isn't a reason to wait, self-diagnose, or seek out imaging before pursuing care. If ADHD symptoms are affecting your work, relationships, or daily functioning, a structured clinical evaluation remains the most reliable, evidence-based path forward—today, not someday.
Siya Health offers physician-led, telehealth ADHD evaluation and care for adults, built on clinical history and standardized assessment—not imaging.
Book Free Meet & Greet — a low-pressure first conversation to see whether Siya Health is the right fit, with no commitment required.
Start an ADHD Evaluation — if you're ready to move forward, this is where a structured, physician-led evaluation and care plan begins.
References
- Bu X, et al. "Mapping ADHD Heterogeneity and Biotypes by Topological Deviations in Morphometric Similarity Networks." JAMA Psychiatry. 2026. doi:10.1001/jamapsychiatry.2026.0001.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). Attention-Deficit/Hyperactivity Disorder diagnostic criteria.
- National Institute of Mental Health (NIMH). "Attention-Deficit/Hyperactivity Disorder (ADHD) in Adults." NIMH educational materials.
- Centers for Disease Control and Prevention (CDC). "Attention-Deficit/Hyperactivity Disorder (ADHD) in Adults." CDC educational materials.
- Barkley, R.A., & Murphy, K.R. "Deficient Emotional Self-Regulation in Adults with ADHD." Peer-reviewed literature on emotional regulation and ADHD.
- Faraone, S.V., et al. "The World Federation of ADHD International Consensus Statement." Neuroscience & Biobehavioral Reviews. Peer-reviewed consensus on ADHD heterogeneity, diagnosis, and evidence-based care.