Parkinson’s, ADHD Risks Highlighted in Genomic Study of Brain Volume
A new international study, including almost 75,000 participants worldwide, identifies 254 genetic variations influencing brain volume and the likelihood of ADHD and Parkinson’s disease.
November 17, 2024
Brain volume, and the genetic variants that influence it, is tied to ADHD and Parkinson’s disease risks, suggests one of the most extensive international studies to date on DNA and brain structure.1
The new study, published in Nature Genetics, examined how brain size and genetic differences influence key subcortical or ‘deep brain’ regions crucial for memory, emotional regulation, proprioception, sensory processing, and responses to rewards and punishments.
A team of 189 researchers from 45 countries analyzed data from genome-wide association studies (GWAS) and magnetic resonance imaging (MRI) brain scans of 74,898 participants across 19 countries. They identified 254 genetic variants that impact brain volume and the likelihood of developing ADHD and Parkinson’s disease.
“Genetic variants associated with larger brain volumes in key brain regions also increase the risk of Parkinson’s disease, while variants linked to smaller brain volumes in key regions are associated with an increased risk of ADHD,” said Miguel Rentería, Ph.D., study principal and associate professor at the Queensland Institute of Medical Research (QIMR Berghofer) in Australia, in a statement. “These findings suggest that genetic influences that underpin individual differences in brain structure may be fundamental to understanding the underlying causes of brain-related disorders.”
However, more studies are needed on the causal relationship between genes and brain-based diseases. “It’s worth noting that these are correlations, not causal relationships, and so interpretation must be approached with caution,” Rentería said.
“My theory is that the underlying mechanisms involve genes crucial to brain development, growth, and aging processes,” Rentería told Medical News Today. “We plan to further investigate to identify the exact biological pathways involved. Understanding these mechanisms could illuminate how brain structure impacts susceptibility to both neurodegenerative and psychiatric conditions, potentially guiding future therapeutic strategies.”
The researchers used data from the Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) consortium, an international effort led by Keck School of Medicine of USC; the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) at Baylor College of Medicine; the UK Biobank; and the Adolescent Brain Cognitive Development (ABCD) study.
ADHD and Parkinson’s Disease
According to the World Health Organization and the Centers for Disease Control and Prevention, rates of Parkinson’s disease and ADHD continue to rise.
In 2018, researchers from the University of Utah Health found that the risk of early-onset Parkinson’s disease and similar disorders is 2.4 times greater among patients with ADHD than it is among individuals of the same gender and age without ADHD. The study, published in Neuropsychopharmacology, examined medical records from the Utah Population Database (UPDB) of 31,769 patients with ADHD and 158,790 individuals without the condition.2
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1 García-Marín, L. M., Campos, A. I., Diaz-Torres, S., Rabinowitz, J. A., Ceja, Z., Mitchell, B. L., Grasby, K. L., Thorp, J. G., Agartz, I., Alhusaini, S., Ames, D., Amouyel, P., Andreassen, O. A., Arfanakis, K., Arias-Vasquez, A., Armstrong, N. J., Athanasiu, L., Bastin, M. E., Beiser, A. S., … Rentería, M. E. (2024). Genomic Analysis of Intracranial and Subcortical Brain Volumes Yields Polygenic Scores Accounting for Variation Across Ancestries. Nature Genetics. https://doi.org/10.1038/s41588-024-01951-z
2 Curtin, K., Fleckenstein, A.E., Keeshin, B.R., et al. (2018). Increased Risk of Diseases of the Basal Ganglia and Cerebellum in Patients with a History of Attention-Deficit/Hyperactivity Disorder. Neuropsychopharmacology. https://doi.org/10.1038/s41386-018-0207-5
