I know XR works on and off, but sometimes I swear IR does the same thing. It will last for a few hours and then it's gone. Sometimes I feel like it kicked back in even though it has been a while since I last took it :confused:

Just because you have ADD doesn't mean you can never concentrate on your own. When you think the IR is kicking in again, hours after it's worn off, maybe you're just focusing all by yourself. IR is supposed to wear off after a few hours (4-6 hours, usually), but it doesn't generally kick back in without another dose. Give yourself some credit! :)