I don't drink much caffeine. I'll occasionally have a Red Bull, Rockstar, or Mountain Dew Kickstart, but that's about it.

Even when I drink 2 energy drinks in a row, it doesn't do much for me mood wise.

Now, if I'm manic already, it certainly feeds the mania. It keeps me up at night, and the less sleep you have, the worse mania becomes (at least in my experience).