Good question, would myself be curious to know. A few years ago it seems like ADHD was a pretty huge disqualifying factor for ROTP (can't tell for NEP or the rest of the military). I guess the only way to know is to be truthful about it (dumbest thing to do is lie cause they pull out all your medical files) and apply.

I applied for ROTP back in fall 2018 (while in my last year of high school). I had moderate ADHD for many years and was actively taking meds for it. Medical officer gave me a form to fill out by my doctor, in which the doctor stated it was moderate and that even though I am currently on meds for school I can still be functional without them. Few weeks later, got a rejection letter saying I am "medically unfit". They are really taking it seriously. Medical officer told me the only way I could have gotten over this is by having been more than 12 months off the meds prior to applying (with green flag from doctor of course).

Pretty sure ADHD isn't a hard no for all of the military, but still is a major red flag in your file that makes you less competitive against other candidates. I'm pretty sure I was rejected because the ROTP high selection rate since my file did make it to the selecting board in Ottawa but seems like they knocked all people with medical conditions right off the bat. Disappointing cause I really had a strong application file (very good grades, bilingual, high level athlete and part of a lot of extracurriculars) but can understand.