Caffeine is weird for me. Sometimes I can drink like 5 to 7 cups then go right to sleep afterwards. Other times it gives me an energy boost, which I often need. I think it can exacerbate things during mania, but for myself I don't think it causes it. I do have a bad habit of drinking cup after cup of it when I'm experiencing hypomania or mania in attempt to intensify the euphoric feelings though.