I've also had this terrible switch. From tre darkest depression and then upp to hypomania or mania in a few days, sometimes ours, and then down again next day. Once it was when I got a new medicine and several times' when my ssri-med was changed in dose. Stress, even a little bit, can make me hypoman and then my hallucinations are back (I hear voices etc). I think that we who are bipolar are very, very sensitive to meds and of course ECT as well. Hugs to all of you