I think it can be common for hypomania to turn into a mixed state. This is what happens to me sometimes and now is a perfect example. I was euphoric for hypomanic for weeks then this hit. Loved the hypo, had a great time so didn't take meds to stop it but now I wish I had as the fun is not worth this hell. They are distinct episodes for me, rather than switching rapidly. Before i was hypo I had been stable for almost two months. Before that I was psychotic manic and this feels like the beginnings of that episode. Sorry, I'm rambling...