My son became aggressive and mean every time we put him on stimulants, so I would discontinue them and he'd go back to normal right away. I don't know if it increased his attention span, but it wasn't worth it to us to have him the way he was on them. Not telling anyone else what to do, but I could see they were bad for him and, since you don't need to wean from them, I just tossed them out. Not advising it, but that's what we did.