Researchers pinpointed a key difference in brain architecture between children and teens with attention deficit hyperactivity disorder (ADHD) and those without.

The research team looked into the brains of over 750 young people and found a lag in how quickly the brain forms connections within and between key brain networks in those suffering from ADHD, the University of Michigan Health System reported.

The findings reveal less-mature connections between a brain network that controls internally-dictated thought and one allowing individuals to focus on externally-directed tasks. This finding could help explain why people with ADHD have so much trouble staying focused.

The research could also one day allow doctors to use brain scans to diagnose ADHD. To make their findings the researchers used advanced techniques to analyze a large pool of detailed brain scans encompassing 275 children and teens with ADHD as well as 481 without the condition. 

The team used function magnetic resonance imaging (fMRI) to show brain activity during a resting state, allowing researchers to see how a number of brain networks communicated. The team found lags in development of connection in the  internally-focused network, called the default mode network or DMN, and in development of connections between DMN and two networks that process externally-focused tasks, often called task-positive networks, or TPNs," University of Michigan Health System  reported

"We and others are interested in understanding the neural mechanisms of ADHD in hopes that we can contribute to better diagnosis and treatment," said lead author Chandra Sripada, M.D., Ph.D, an assistant professor and psychiatrist who holds a joint appointment in the U-M Philosophy department and is a member of the U-M Center for Computational Medicine and Bioinformatics. "But without the database of fMRI images, and the spirit of collaboration that allowed them to be compiled and shared, we would never have reached this point."

The findings could launch a new phase of ADHD research that examines the components of networks that have a maturational lag.

"This study provides a coarse-grained understanding, and now we want to examine this phenomenon in a more fine-grained way that might lead us to a true biological marker, or neuromarker, for ADHD," Sripada said.

The findings were published in a recent edition of the Proceedings of the National Academy of Sciences.