Norepinephrine is another neurotransmitter highly implicated in ADHD.
Quoting from Wikipedia: Norepinephrine release is lowest during sleep, rises during wakefulness, and reaches much higher levels during situations of stress or danger, in the so-called fight-or-flight response. In the brain, norepinephrine increases arousal and alertness, promotes vigilance, enhances formation and retrieval of memory, and focuses attention; it also increases restlessness and anxiety.
The trouble of being to regulate wakefulness has been in my personal experience more pronounced than attention jumping around. But that’s likely fairly individual. I wouldn’t be surprised if the inattentive subtype & hyperactive subtype categories we use now were related to balance of these two.
Even if it doesn’t bring anything novel having confirmed results is good in science.
Open access PDF of the study can be obtained here: https://www.cell.com/cell/fulltext/S0092-8674(25)01373-X