A recent study published in JAMA Psychiatry analyzed brain scans and neurochemical signals from 1,154 people with attention deficit hyperactivity disorder (ADHD) and found evidence for three distinct biotypes of the condition. The researchers report that ADHD does not affect everyone’s brain activity the same way, and that each biotype appears to have different patterns of structural and chemical brain alterations.
The three biotypes identified were:
– Severe combined with emotional dysregulation
– Predominantly hyperactive/impulsive
– Predominantly inattentive
The predominantly inattentive group showed changes in brain regions tied to sustained attention and filtering distractions. The hyperactive/impulsive group showed disruption in circuitry that governs impulse braking and action regulation. These findings broadly align with clinical observations and DSM-5 symptom clusters.
The severe combined type with emotional dysregulation showed the most widespread brain alterations, persistent emotional dysregulation over time, and preliminary signals of higher rates of mood disorder comorbidity. Neurochemically, this group showed involvement across multiple neurotransmitter systems simultaneously — including serotonin, dopamine, acetylcholine, and histamine — which may help explain why some people with ADHD do not respond well to stimulant medication alone.
Experts who were not involved in the study say the results could help move ADHD care away from a one-size-fits-all approach. If distinct neural circuits and neurotransmitter systems underlie different biotypes, then treatments tailored to those specific biological patterns could be more effective than the current standard practice of diagnosing and then prescribing stimulants with dose adjustments.
However, researchers and clinicians caution that more work is needed. The study’s correlations between neural networks and the three biotypes support ongoing research, but large, well-controlled clinical trials will be necessary to demonstrate that particular treatments or compounds benefit specific symptom clusters or biotypes.
Diagnosing ADHD involves multiple steps; there is no single test. Current treatment typically combines behavioral therapies and medication and varies by age. For children under 6, parent training in behavior management is usually the first line of care before medication. For children aged 6 and older, treatment commonly includes behavioral therapy plus medication when appropriate. Behavioral therapy helps build self-regulation skills and often involves parent training. Medications fall into stimulant and non-stimulant categories, and families should work closely with healthcare professionals to find the right approach.
The study’s authors and outside experts emphasize the promise of these findings for moving toward personalized therapeutic strategies, while also noting the need for further research to translate neurobiological subtypes into specific clinical recommendations.
