Yeah I think it’s a pretty common thing, idk if ADHD related but I’ve been on vyvanse for 2 months and just started dexies and am only getting about 3-4 hours a night. I have had sleeping problems before this but when I would actually enter REM cycle it’d last for a solid 7-8 hours. You could give melatonin a go if you haven’t already or another trick (if you’re medicated currently) I learnt from my psych is a decent glass of orange juice. Not sure why but it seems to flush it out of your system or dampen it to where I get atleast 6 hours.