I am literally in this boat right at the moment. I've been treated for MDD for the past three years with some success, however I have also realized (especially looking back) that being on antidepressants alone actually triggered/enhanced my hypomanic/manic episodes, and did help me from reaching the super low-lows, but I was still pretty bad. Which has definitely made me question why I am on this "rollercoaster" and not getting better.

So I started doing tons of research on bipolar disorder, and was literally nodding along while reading about it. It was kind of a eureka moment that finally explained my behaviours.

I'm actually seeing my pdoc tomorrow morning, and being started on a new medication to FINALLY start treating this. So, fingers crossed that this will be a positive thing, and a step in the right direction.

But to answer your question, yes, I have been suspecting for a while that I was originally mis-diagnosed, and did infact have BP to some degree.