Joel Nigg: recent publications

February 16, 2023Researchers have “refined the genetic architecture of ADHD” after identifying 27 variations in genetic code that are most present in people with the attention deficit hyperactivity disorder. A Danish-led international genome-wide association study (GWAS) published in Nature highlighted these and 76 probable risk genes — including “brain-expressed genes” involved in development and genes known to influence other psychiatric disorders.

1The study identified 27 ADHD risk loci, or locations of a gene or mutation on a chromosome. Researchers then linked these loci to 76 ADHD risk genes.

They found that many of the genes thought to influence ADHD also influence early embryonic brain development.“This emphasizes that ADHD should be seen as a brain developmental disorder, and that [ADHD] is most likely influenced by genes that have a major impact on the brain’s early development,” said Ditte Demontis, one of the study’s authors and a professor at Aarhus University.Researchers estimated that up to 7,300 common genetic variants influence ADHD, highlighting its polygenicity. They observed that common variants were often found in genes expressed in the frontal cortex, which is responsible for attention and working memory, and in genes expressed in midbrain dopaminergic neurons that control voluntary movement and reward processing.“There was a time about 30 years ago when many scientists — and the general public — thought that… we would find the [one] gene for ADHD, bipolar disorder, autism, and so on,” said Joel Nigg, Ph.D., in a recent ADDitude webinar.

“That is clearly wrong. We now know after 25 to 30 years of extensive genetic research that lots of genes are involved in these conditions; there’s lots of overlap

Joel Nigg