Researchers find how neural and genetic factors influence the diagnosis of ADHD

For the study, the US-based research team turned to brain imaging analysis of certain regions in 315 participants aged 7-13, the majority of which were diagnosed with ADHD.

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New research released online in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging showed how brain function changes are correlated with genetic factors influencing diagnoses for attention deficit hyperactivity disorder (ADHD).

“Attention-deficit/hyperactivity disorder (ADHD) has substantial heritability, and a recent large-scale investigation has identified common genome-wide significant loci associated with increased risk for ADHD,” according to researchers. “Along the same lines, many studies using noninvasive neuroimaging have identified differences in brain functional connectivity in children with ADHD.”

“We attempted to bridge these studies to identify differences in functional connectivity associated with common genetic risk for ADHD using polygenic risk score (PRS).”

For the study, the US-based research team turned to brain imaging analysis of certain regions in 315 participants aged 7-13, the majority of which were diagnosed with ADHD. Researchers used data from the Psychiatric Genomics Consortium as a discovery set, the findings stated.

In their examinations of different brain regions, resting-state non-invasive magnetic resonance imaging scans were used to study brain communications from the regions. “Magnetic resonance imaging was used to evaluate resting-state functional connectivity of targeted subcortical structures,” the study says.

Researchers determined that connectivity in one region of the brain was correlated with an increased risk of ADHD. In a another region, genetic effects were compensated and the risk for diagnosis of the neurodevelopmental condition was lower.

“The functional connectivity between 2 region pairs demonstrated a significant correlation to PRS: right caudate–parietal cortex and nucleus accumbens–occipital cortex. Connectivity between these areas, in addition to being correlated with PRS, was correlated with ADHD status,” the findings showed.

“The connection between the caudate and the parietal region acted as a statistical suppressor, such that when it was included in a path model, the association between PRS and ADHD status was enhanced.”

“Our results suggest that functional connectivity to certain subcortical brain regions is directly altered by genetic variants, and certain cortico–subcortical connections may modulate ADHD-related genetic effects,” the study’s co-authors concluded.

To identify the risk of developing ADHD, genetic scores may no longer be sufficient as the new findings detailed a neural approach detrimental toward diagnosis. Future research should consider combining both genetic and neural factors when determining risk of ADHD diagnosis.

© Image courtesy of IMC