Stimulants are performance enhancers for anyone, not just people with ADHD. That's why they're controlled meds and have a street value!

Not sleeping for 2 days is not the usual reaction, like others said. It could have been the wrong dosage, or depending on the dose, it could also mean that you don't need it. For me, the standard dosages last most of the day, but peter out around 3 PM, so I often had to take a second dose at mid-day to stay functional all day.

The first time I took ADHD meds, they weren't my own, and they actually made me function normally! The second time, it was a higher dose, and I got so high I was hallucinating (that would likely be due to bipolar, I've occasionally had psychotic symptoms when triggered by the wrong rx's.) So, lesson learned: go to a doctor and make sure they get it right, because it's potentially dangerous stuff to screw around with.

I actually had my 3rd ADHD evaluation this week. This time it was a computer-based test, which is somewhat more objective than the usual clinical interview self-report. It confirmed the obvious, so I'm going back on Concerta as soon as my insurance authorizes it.