This is the same so far for me - even mild stimulants like caffeine (I know, it's a different underlying chemical process) have less effect - I could drink coff

This is the same so far for me - even mild stimulants like caffeine (I know, it's a different underlying chemical process) have less effect - I could drink coffee right before bed without much/any issue. And still trying to find a stimulant that helps with ADHD myself (only on my 2nd one (Ritalin, Adderall), and pretty mild doses so far). But that is also pretty common for me - I've always had fairly high drug resistance, as it were (need higher doses to feel any affect), so I don't know if that is at all specific to ADHD and those medications.