I wonder if Bipolar Disorder, like autism, falls under a spectrum rather than discreet diagnoses. This would mean there would be infinite degrees of mental illness, rather than just two or three. I have experienced full-blown mania several times and could be classed as BP I, but I don't really believe I am. I don't believe I can be classed as BP II either, because of the mania I've experienced. I fall somewhere in between.