That would probably be dangerous. The drugs prescribed for ADD can induce psychotic episodes, and cause mood swings, and otherwise have negative psychological

That would probably be dangerous. The drugs prescribed for ADD can induce psychotic episodes, and cause mood swings, and otherwise have negative psychological effects. Switching between different stimulants could amplify the risk of such episodes, or complicate treatment should such a patient have such an episode. I would be a bigger fan of moderating the drugs. Don't use the drugs on weekends or holidays; use lower doses on days where it is OK to goof off a bit or days where the workload is light. I suspect that doing this with children would be a good lesson in and of itself, in that they can see that work and play can be separated and that the withdrawal symptoms from a drug can be overcome (this could also serve as a way to identify people who have some innate problem with drug dependence before they get into trouble). Of course, there is also the matter of school being so boring and so undesirable that children need to have pristine focus just to survive. Perhaps it would be best to solve that problem first, before using drugs to keep children focused on "busy work."