[eli_gottlieb]

I tried the stuff as a kid and in undergrad -- I was diagnosed with ADHD. It very much helped me concentrate, but stopped me from thinking creatively, clamped down on my ability to think socially, and gave me damned irritating headaches.

Today, I'm more successful with no drugs and an improved work ethic. And less headachey.

[hikz]

  I tried the stuff as a kid and in undergrad 

How often and when did you take it? Did you take it during holidays when you didn't have to study?

[eli_gottlieb]

I tended to use it only on workdays, and to take something like 10mg once per day. I think I had slow-release at one point.

But again: I had a prescription, from a doctor, due to a diagnosis. The experience remained quite unpleasant, and I don't recommend it to anyone.