My difficult child has been on Ritalin for a couple of months with fairly good results at school. Let's not talk about the rebound . His Dr suggested that Concerta would be a good next step to cover the small bumps in the day he is experiencing. We gave him his first 27mg dose yesterday but it didn't seem to kick in for at least 3 hours! It almost appeared that he wasn't medicated at all for this time. His mood stabalised for about 4 hours in the afternoon but then he was either racing around or very subdued. Couldn't sleep until almost 11:30. Luckily this is not a school day! I know that all drugs have different side effects but am surprised that the long acting version of the drug can be so different to the short acting version. Is this something others have experienced or is it just my bundle of joy! Or maybe I don't have full details of this drug's inter reactions.