Thanks, that's a really useful answer, and you're far from alone. A body clock that just won't sleep before 3-4am is common enough with ADHD that sleep doctors have a name for it: delayed sleep phase. Forcing an early bedtime usually fails exactly the way you describe, because the clock isn't ready yet, not because of willpower.
The stimulant-makes-me-sleepy thing comes up a lot too. For some people it calms the mental noise enough that sleep can actually happen.
Two things people with a late clock sometimes find useful, if they ever want to shift it (and it's completely valid not to, if your life allows a 4am-noon schedule):
- Light timing: bright light soon after your natural wake-up, and dim screens and lights in the late evening. It moves the clock slowly, maybe 15-30 minutes a step.
- Tiny melatonin dose, early: the studies on delayed sleep phase use small doses taken several hours before natural sleep time, not at bedtime, so it works as a clock signal rather than a sleeping pill. Worth checking with a doctor first, especially alongside other meds.
Does it stay at 4am on days off too, or drift even later?