On and off is the worst thing you can do, because it messes up with your brain chemistry... if you go on and off too often, your body doesn't have time to adjust so you are whacked up.

If you cannot tolerate a drug, come off securedly to either try something else or try chem-free... if you feel you need something to help you out... you need to stick with it for longer time and come of slowly if you feel it's the time. Stopping abruptly, taking it sporadically... is no good.