I’m not going to argue if it’s identical to ADHD chemically. I’m not sure we have the level of understanding of the low level mechanisms to differentiate (if it even is actually different), or even that ADHD is “one mechanism” and not a bundle of similar mechanisms of different types of disregulation with similar outcomes, because diagnosis of any mental difference is effectively all about checking boxes on patterns of behavior.

But even if there’s something you can point to as clearly a distinguishing factor to say “this isn’t ADHD as we’ve defined it”, which I’m not sure you can, I’m not sure how you say they’re not similar or related.