Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) seem to have a lot in common. Many people with one disorder also have the other, leading researchers to suggest that there may be common brain characteristics between the two disorders. However, new research from the University of Texas at Houston and the Oregon Health and Science University in Portland suggests that autism and ADHD have disparate brain connectivity patterns. The brain region known as the ‘rich club network’ is affected in both disorders, but the way in which the rich club network connects the brain differs in autism and ADHD.
The researchers scanned the brains of children aged 7 to 13. They evaluated 20 children with ADHD, 16 children with autism, and 20 typically developing children. The researchers mapped the neurons in the brain and analyzed which neurons synched up when the brain was at rest. Using this information, they identified the most connected brain regions, which revealed the shape of the children’s rich club networks. The rich club network is a hub of neural connections that integrates sensory input and cognitive processes from different brain regions. This network is critical to carrying out complex, but mundane tasks, like driving a car.
Both children with autism and children with ADHD exhibited connectivity issues in the rich club network. Children with autism had rich club networks with too many weak connections. Children with ADHD had fewer connections than the children in the control group.
This study could explain some of the apparent inconsistencies in brain connectivity studies focused on people with autism. The findings also suggest that having more neural connections does not necessarily lead to stronger functional connectivity. This could help researchers better understand connectivity issues in autism and ADHD.
This research is published in the journal Human Brain Mapping.