Study: Brain Structure Differences in Boys May Reveal Genetic Risk for ADHD
New research shows that some children with symptoms of ADHD have abnormally small volume in specific structures of the brain. This study from the Barcelona Institute for Global Health suggests that ADHD’s genetic variants differ between boys and girls with the condition.
January 29, 2019
A new study1 published in the Journal of the American Academy of Child & Adolescent Psychiatry suggests a link between childhood brain structure and the genetic risk for developing ADHD, particularly in boys. The study, which examined the relationship between polygenic scores (PGS) for psychiatric disorders and brain MRI structural measurements, shows a relationship between smaller-than-average brain volume and ADHD symptoms.
Researchers gathered data from a sample of 1,139 10-year-old boys and girls studied in the Dutch Generation R Study cohort. The participants’ genetic susceptibility to ADHD was obtained using polygenic risk scores based on genetic data. The scores were calculated in accordance with the most recent findings of genome-wide association studies.
Children with higher polygenic scores related to intelligence or educational attainment tended to have a larger total brain volume. By contrast, participants with higher polygenic scores related to ADHD showed smaller volume in the caudate nucleus — one of the structures of the brain.
While this morphological difference in the caudate nucleus could explain the genetic risk for ADHD and attention in boys, the association was not observed in girls, suggesting that the genetic variants associated with ADHD may act differently in the brains of boys and girls.
Since the data was collected at one specific point in the lives of the participants, more research is needed involving measurements of the brain over time to determine whether changes in developmental trajectories are related to the polygenic risk for psychiatric disorders or cognitive traits.
1 Silvia Alemany, Philip R. Jansen, Ryan L. Muetzel, Natália Marques, Hanan El Marroun, Vincent W.V. Jaddoe, Tinca J.C. Polderman, Henning Tiemeier, Danielle Posthuma, Tonya White. “Common Polygenic Variations for Psychiatric Disorders and Cognition in Relation to Brain Morphology in the General Pediatric Population.” Journal of the American Academy of Child & Adolescent Psychiatry (January 2019). https://jaacap.org/article/S0890-8567(19)30007-3/fulltext