Attention deficit hyperactivity disorder (ADHD), one of the most common neurodevelopmental disorders found in children, is known to involve alterations in neurochemistry, including the disruption of dopamine and norepinephrine signaling. However, the role of amino acids, which also serve an important role in brain function, has not been as extensively studied with regard to ADHD pathology. A research team from RUDN University recently sought to examine amino acid profiles associated with ADHD by testing the blood serum of more than 100 children using high-performance liquid chromatography (HPLC).
In the study, blood serum samples were collected from 71 children with ADHD and 32 neurotypical children with no diagnosed disorders, and amino acid profiles were analyzed through an HPLC-UV detection method. The analysis revealed that the amino acid profiles of children with ADHD differed from those of children without ADHD. The most significant difference was in hydroxyproline concentrations, which were on average 42% higher in children with ADHD compared to neurotypical children.
Aspartate and glutamate concentrations were also both 7% higher in children with ADHD, while an analysis of essential amino acids found 29% lower histidine levels compared to neurotypical children. Proline and glutamine were also 20% and 10% lower in children with ADHD, respectively. From these altered values, researchers calculated a 29% lower proline/hydroxyproline ratio in children with ADHD, and a 28% lower glutamine/glutamate ratio. The research was published in Biomedical Reports.
“The observed alterations in Pro/Hypro and Gln/Glu levels and ratios are likely associated with the coexisting connective tissue pathology and alterations in glutamatergic neurotransmission in ADHD, respectively,” said Anatoly Skalny, study author and head of the RUDN Department of Medical Elements Studies. “However, further in vivo and in vitro studies are required in order to investigate the detailed mechanisms linking amino acid metabolism with ADHD.”
Further study of ADHD pathogenesis can ultimately aid in the development of better treatment and management strategies for the disorder, Skalny said.