I just made the same mistake a few weeks ago---was feeling very stable, and thought I'd trying cutting my Geodon dose in half. BAD IDEA. Within a couple of days I was experiencing something like dysphoric hypomania---irritable, jittery, pissed-off for NO reason, couldn't keep still and so on. Stupid me......as soon as I realized what was causing it, I went right back on the 80 mg and have been fine ever since.