An Israeli-led international trial of ADHD children shows that a combination of cognitive training and brain stimulation modifies neural efficiency markers to a profile more typical of non-ADHD children. And some of the changes lasted weeks after treatment ended.
https://www.jpost.com/health-and-wellness/mind-and-spirit/article-880352
https://www.sciencedirect.com/science/article/pii/S2213158225001962?via%3Dihub