I believe you. That said it seems to vary wildly.<p>From what I have witnessed it even varies with type of the same stimulant from person to person, even within a family. (In a case I know all too well the recipient get tongue swelling as well as clenched jaws[0] on R XR at 40mg&#x2F;day but has absolutely no issues with doses from 40 - 80 mg&#x2F;day of the standard one. Oh, and the other person in this study, the brother of the first, went into spiraling weight loss at 60mg&#x2F;day but prefer XR.)<p>Also playfulness seems to be preserved in these two cases. The best explanation I can come up with is: lowers the &quot;interesting&quot; threshold so that driving according to the speed limits is less intensely boring etc.<p>[0]: of course this can be reactions to additives of XR but they are commonly referred to as side effects of R itself.