I was first diagnosed as MDD with anxiety at my college Junior year. I was prescribed Lexapro which did good for me for a few months and then I began feeling extremely happy for no reason, on top of that I was getting little sleep, spend a couple thousand shopping and taking out multiple credit cards. Also when this was happening I stopped going to the college counseling center and just enjoyed "feeling good" after being depressed. My parents and I decided to see a pdoc after I started realizing what I was doing and that was when I was diagnosed BP1 (rapid cycling came later). Weirdly enough, I haven't had a maniac episode since, only hypomania and depression.