anyway, i was diagnosed with ADD 15 years ago in 10th grade or so. My parents didn't know what it does and just signed off waivers and i was on Ritalin for a year or so. It was NOT a night and day for me, maybe it was but wasn't as pronounced. My grades didn't improve significantly, but I did feel more euphoric and was a bit more social after i was on it (before i was an introvert big time). I gave one pill to my friend before a final exam, and he was GLUED to his textbook and studied 4 hours straight (yeah yeah, i know it is wrong, he could have allergic reaction or died, i was a kid). But I never had the same affect, i stopped using it once i got to college.
Now, in my 30s, I still do have focusing issue, and I don't know will Ritalin or meds be a solution, and i wonder had my college life would have been different if I was on meds.
I would also agree on what another member suggested: coffee calms me down and allow me to focus slightly better.