Yeah, Rudey. Stay away from Adderall and Ritalin! That stuff will mess you up. I know that from taking Ritalin for 4 years and Adderall for 2 years, not recreationally, but for theraputic reasons.
If you have trouble concentrating and staying awake here's to remedies:
*Drink Hansen's Energy citrus soda, it has all the good stuff to "hype" you up, such as, 80 mg. of caffiene, b-vitamins, ginseng, taurine, etc. If you don't know what I am talking about, it's in a tall green soda can,
by the health food section, it's a little expensive ($1.99), but it's worth it.
*Run bitch run!
When you exercise, your body releases chemicals like dopamine, adrenaline, endorphins, seratonin, etc. That can help concentration, but don't over do it or it will get worse!