Distinct Brain Connectivity Patterns Differentiate Autism and ADHD, New Study Shows

Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are prominent neurodevelopmental conditions affecting millions worldwide, with estimated prevalence rates of about 1–3% for autism and 5–7% for ADHD. While autism typically involves challenges in social communication, repetitive behaviors, and heightened sensory sensitivities, ADHD is characterized by hyperactivity, impulsivity, and difficulty focusing. Notably, these conditions often co-occur, with studies indicating that 50–70% of individuals with ASD also display symptoms of ADHD. However, despite their frequent co-existence, the neurobiological differences between them remain partially understood.

Recent large-scale research conducted by scientists at the National Institutes of Health and King's College London has shed light on this issue. Their comprehensive analysis compared brain connectivity patterns in children and adolescents diagnosed with ASD and ADHD. Published in Nature Mental Health, the study analyzed data from over 12,700 young individuals, exploring how various brain regions communicate in each condition.

The researchers focused on key brain areas including the thalamus, a relay hub for sensory and motor signals, and the putamen, involved in movement and learning, among others that regulate attention, emotions, and self-awareness. They discovered that autism traits are associated with weaker connections between these regions and neural networks, whereas ADHD traits tend to show stronger connectivity in the same areas.

Specifically, autism was linked to reduced connectivity among the thalamus, putamen, salience networks, and frontoparietal systems, whereas ADHD exhibited increased connectivity in these regions. Both groups showed hyperconnectivity between the default mode network and dorsal attention network, but these patterns were subtly different and often associated with distinct behavioral traits.

Overall, the findings suggest that although autism and ADHD may frequently occur together, they are characterized by distinct neural signatures. This insight spells important implications for the development of targeted diagnostic tools and personalized therapeutic interventions, considering the different underlying functional connectivity patterns. Ongoing research in this domain continues to enhance our understanding of these complex neurodevelopmental disorders.

For more detailed information, refer to the original study: Luke J. Norman et al, "Cross-sectional mega-analysis of resting-state alterations associated with autism and attention-deficit/hyperactivity disorder in children and adolescents," Nature Mental Health (2025).