Research Finds ADHD-Related Aggressive Behavior is Genetically Coded

An international collaboration of researchers has found several genetic variants that increase the risk of aggression in children with attention-deficit hyperactivity disorder (ADHD), according to a study by the Danish iPSYCH consortium and the Psychiatric Genomics Consortium.

These findings mark the first time that investigators have found positions in the genome that increase the risk of getting ADHD with disruptive behavior disorders (DBDs). DBDs are child psychiatric disorders characterized by antisocial and aggressive behaviors. The findings could be used to gain an understanding of the biology that leads to ADHD with DBDs, which can be found in 20% to 30% of children with ADHD, according to the study authors.

The team analyzed genomes from 3802 children with ADHD and DBDs and 31,305 children without either diagnosis. They identified 3 specific locations in the genome that increase the risk of having both diagnoses. One variant was found on chromosome 11, which seemed to increase the risk of aggressive behavior, according to the press release.

The researchers added that their findings suggest that the aggressive behavior in children with ADHD and DBDs can be partially explained by genetics.

“We’ve also compared our results with results from another large genetic study of aggression in children who do not have a child psychiatric disorder,” said researcher Ditte Demontis, PhD, in a press release. “We discovered that the genetics involved in ADHD with DBDs to a great extent is shared with the genetics involved in aggression in the general population.”

Demontis said the study results revealed just a small part of the biological mechanisms involved with ADHD and DBDs, both of which are complex disorders affected by both environmental and genetic factors. The results were published in Nature Communications.

“In other words, the genetics that affect aggression in children with ADHD and DBDs are the same as the genetics that underlie aggression in general,” Demontis said in the press release. “Children with ADHD with behavioral disorders have been unlucky and have received many of the genetic variants that increase the risk of aggressive behavior.”

The study is a genome-wide association study, which means researchers analyzed genetic variants distributed across the entire genome in order to identify variants that are over-represented in people with ADHD and DBDs compared to people without the disorders.

“The genetic risk [of ADHD and DBDs] is comprised of many genetic variants, each of which increases the risk slightly,” Demontis said in the press release. “This means that the genetic variants we have identified in this study only represents the tip of the iceberg.”

REFERENCE

ADHD: Aggressive Behavior Is Genetically Coded. News release. iPSYCH; March 10, 2021. Accessed August 2, 2021. https://ipsych.dk/en/news/#news-19837