Post #5269

Autism and ADHD May Share a Hidden Brain-Gene Signature A study published in Molecular Psychiatry suggests that the biology underlying autism and ADHD does not fit neatly into current diagnostic categories. Although clinicians have long recognized that autism and ADHD frequently occur together, scientists have struggled to pinpoint the shared mechanisms behind that overlap. Researchers from the Child Mind Institute and collaborating centers found that the intensity of autism symptoms, rather than whether a child carries a diagnosis of autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD), is linked to specific patterns of brain connectivity and gene activity. The results add to a growing shift in psychiatry toward understanding neurodevelopmental conditions along dimensions of traits and biology, rather than as strictly separate disorders. Symptom severity reveals shared biology The research team, led by Adriana Di Martino, MD, Founding Director of the Autism Center at the Child Mind Institute and Senior Research Scientist, analyzed resting-state functional MRI scans from 166 verbal children between the ages of 6 and 12 who had been diagnosed with autism or ADHD (without autism). Resting-state imaging allows scientists to measure how different brain regions communicate while a person is not engaged in a specific task, offering insight into underlying network organization. Children with more pronounced autism symptoms showed stronger connectivity between regions in the frontoparietal (FP) and default-mode (DM) networks. These networks play central roles in executive functioning, attention, and social cognition. In typical development, connectivity between these networks tends to decrease over time as the brain becomes more specialized. The heightened connectivity observed in children with greater symptom severity suggests differences in how these networks mature. Importantly, this pattern appeared across the full group of children, regardless of whether they were formally diagnosed with ASD or ADHD. The connectivity differences also aligned with maps of gene expression in the brain, particularly genes involved in neural development that have previously been linked to both conditions. This overlap points to biological pathways that may cut across diagnostic labels. “We see in the clinic that some children with ADHD share symptoms qualitatively similar to those observed in autism, even if they do not fully meet the diagnostic criteria for ASD,” says Dr. Adriana Di Martino. “By focusing on shared brain–gene expression patterns linked to autism symptoms across both ASD and ADHD, we can point towards a shared biological basis of these clinical observations. Our findings provide a more nuanced, dimensional understanding of neurodevelopmental conditions.” Source:SciTechDaily @EverythingScience