I had negative side effects from the first few I tried, only the ER version of generic ritalin had no side effects. The non-extended version made me jittery and wore off too fast and some of the other newer meds had some really bad side effects.

All of mine were tried as an adult, but I heard that some medications have different effects for the same people in their youth and adulthood or even just over time so changing the prescription might be an option if you go back to an "in" period.