I had no idea. I was diagnosed with MDD and prescribed Paxil when I was 20. I probably went hypo afterwards, because I upped and moved to MO later that year. While living out there, I fell into depression again and was hospitalized while there. The pdocs were just giving me medications without really explaining the diagnosis to me. When I moved back to VA I was on and off medications, still not knowing (at least I don't remember). It wasn't until I went to a pdoc again after another depression that told me I had bipolar depression. I had no idea what she was talking about, but the med she gave me worked. I read more and more about what this bipolar was, and I was like hmm, this does make sense. I was feeling better and somewhat "normal". And from then on I knew that's what it was. I was 27.