Supporting this observation: https://www.frontiersin.org/journals/psychiatry/articles/10....
I've been looking for theories for why 10mg Adderall seems to give me a brief feeling of drowsiness ~30 minutes after taking it.
The state regulation theory (ยง3) in this article might suggest that the process of returning to baseline could feel like sleepiness https://www.frontiersin.org/journals/psychiatry/articles/10....
Which makes more sense if the sleep disorder explanation for ADHD means that the normal feeling of sleepiness is not properly functioning.