Researchers found four gene variants that may be involved in vital brain signaling pathways in a subset of kids with ADHD. This discovery may aid in the development of drugs that target those pathways.

It’s estimated that a half million children in this country have ADHD and these gene variants, which belong to the glutamate receptor (GMR) gene family. While the disorder tends to occur in families, scientists are still uncertain of the exact cause. Drugs prescribed for the condition may not always work, especially when symptoms are severe.

In a recent study published in Nature, 1,000 children with ADHD from a database at the Children’s Hospital of Philadelphia were found to have a considerably greater number of copy number variations (CNVs) on four GMR genes, compared with 4,100 kids in the control group who did not have ADHD. The one with the strongest result was gene GMR5.

Carefully selected GRM agonists could be used in human studies to determine whether they might have potential as therapies for ADHD patients with particular CNVs.