I am taking Methylphenidate (Novartis brand Ritalin 10 mg IR pills) for over 4 years now since I have ADD and the people who are dismissing it as 'kiddy', 'stupid', or 'very subtle' have never had 6 x 30 pills in their hands every time without anyone to stop you from doing too much since I always got way more pills than I needed from my kinda mediocre doc (who has a typical prozac/effexor/any novel promotion-stuffed office but that story doesn't belong in this topic TBH).
At one point it got so bad that I snorted 100 mg when I woke up, got into my favourite games: First Person Shooters like Quake III or Unreal Tournament 1999/2003/2004 and I would beat anyone playing at insane speeds, thanks to my natural reflexes (which were tested under clinical conditions and were about a full second faster than the average person, try some reaction speed test on the web to see what I mean).
Eventually I got into professional gaming and there I needed to get faster, smarter, better etc. to keep up with the best EU players/teams and looking back at those days I am sure other people abused Stimulants to gain an advantage when there is money to be won for the winning team. I played with some of the best players and had winning streaks of 10+ official matches in a row but those years are long gone now... I miss those fast-paced games.
So eventually I started binging for days and would feel so depressed after the crash that I would try to avoid it as long as I could, but no substance has ever been so addictive to me that I needed a line every 3-4 hours or my ADD would hit me so hard like the rebound effect described in the DSM manual. I snorted both street amps and coke a few times and I like my OxyContin and my Benzos(prescribed ofcourse

) but I decided to stop QT after a 3 day binge taking around 250-300 mg every day: short version is that it took me 8 days of intense w/d symptoms and a craving that no other drug matched.
Now I am back on 60 mg daily and have to pick up my recipe every morning at the pharmacy. I no longer weigh around 40 kilos (I was a horrible walking skeleton) since the stuff made me forgot about all my problems and I could easily sit in the same position for a few hours doing absolutely nothing at all... just being 'in the zone' is the best description I can give it and I basically lost 3 years...
I wanted to write so much more but I am tired and digging into your past can get difficult if you know what I mean... so any advice I can offer will take a few hours since I haven't quit really, but got it under control now so I and Methylphenidate will always have a love/hate relationship for me so writing this down is so mentally hard for me, I just need a break for a moment but will be back with some more advice since I have a ton of links/experiences which might be useful...
I will post back later, hopefully being more helpful but the stuff is so addictive for me that I need some time off...
-- Peace o/