A study published in Molecular Psychiatry reports that the severity of autism related traits, rather than a diagnosis alone, is associated with certain brain connection patterns associated with genes linked to autism and ADHD. 

Researchers from the Child Mind Institute and collaborating institutions analyzed resting state brain scans from 166 verbal children ages 6 to 12 who were diagnosed with autism or ADHD. Resting state imaging measures how brain regions communicate when a person is not performing a specific task, allowing scientists to observe how large-scale brain networks are organized. The results suggest that shared biological pathways may help explain why autism and ADHD frequently overlap. 

The research team, led by Dr. Adriana Di Martino, found that children with more pronounced autism-related traits showed stronger communication between the brain’s frontoparietal and default mode networks. These networks support social and executive thinking. 

During usual development, connectivity between these networks decreases over time as the brain systems become more specialized. Stronger connectivity may reflect differences in how these networks mature.

 This pattern of stronger connectivity appeared across the full group of children regardless of diagnosis. Some children with ADHD showed similar connectivity when autism traits were more severe, even without an autism diagnosis.

 Researchers also found that these connectivity differences corresponded with regions where genes involved in neural development were active. These findings support a shift in understanding neurodevelopmental conditions along classification of traits and biology rather than strict categories. Programs such as the Healthy Brain Network are collecting large scale brain and behavioral data collection to expand this approach.