Methylphenidate
"I've had ADD my whole life and just started take this year I'm 19. 
Pros-
You take it in about 30mins it kicks in
Your heart starts pounding you feel a high and then you can focus on something for about 2-3 hour
Cons-
It makes you focus on one thing so if you want to do anything else you can't
It gets rid of your hunger
Give you horrible headaches
Makes you mad at anything when it wears off 
Makes you want to take more and more to feel that high again 
I really don't recommend it."