I see the correlation, not quite the causality, especially in ADHD. I think what is often ignored is the role of feedback loops.

Going to bed late might not be a problem, unless you have to get up early, get a lot of input into your somewhat unrested brain, and finally get some quiet, late at night, when nobody expects anything from you, to process the day. Which keeps you up until late again. That is what seems to happen in my case.

Breaking that cycle with all kinds of interventions (apps, etc) probably does not really work in the long run. The real change comes from less input that causes friction and demands to be processed in the peace and quiet of night. Or just sleep until rested.

Btw: i seem to remember some research that in ADHD the brain prunes synapses less than in most people. Not sure if it was linked to sleep deprivation or anything else.