Transcriptomic Analysis Highlights Brain Gene Expression Differences in ADHD

Gene expression differences affecting neurotransmitter activity in the brains of people with attention deficit hyperactivity disorder (ADHD) versus individuals without the condition are reported in Molecular Psychiatry this week. While recent research has uncovered many rare and common genetic variants that confer risk for ADHD, these studies have relied on imputation from genotype to predict gene expression in different brain regions, limiting their utility. In the newly published study, a team led by National Human Genome Research Institute researchers performed RNA sequencing on post-mortem brain tissue from 60 ADHD patients and matched controls, focusing on two regions of the brain — the caudate nucleus and anterior cingulate cortex — that are implicated in the disorder. They uncover significant downregulation of neurotransmitter gene pathways in the ADHD samples, as well as transcriptomic changes that are also found in other neurodevelopmental and mood disorders. "This transcriptomic evidence points to cortico-striatal neurotransmitter anomalies in the pathogenesis of ADHD, consistent with current models of the disorder," the study's authors write.