What was the tipping point that made your pdoc/therapist conclude you have bipolar?

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.

My therapist was the first one to suspect it. I had recurrent depressive episodes and was having a major one when she started reading her notes and realised that only one week earlier I had felt like I was on the top of the world and now the exact opposite. She went through those notes and saw a pattern which looked like bipolar disorder to her. She contacted my doctor and I was diagnosed with cyclothymia.

A year later I got manic, at first it was just increased creativity and talkativeness, but then it leaded to me wasting all of my money and engaging in risky behaviour. Well it didn't get too bad before I landed back on earth (after 6 or 8 weeks) and went into the deepest depression I had ever had. I was unable to continue my studies, unable to take care of myself, and at some point I realised to seek help and got hospitalised due to a severe depressive episode and diagnosed with bipolar (by a different doctor).

But yes, my therapist was the first one to notice the elevated mood, that was nearly every time followed by depressive mood of some degree.

I started of with a diagnosis of MDD in my teens. When I was in my early 20s, I was finally ready to try medications, after having scripts I'd never filled. I was prescribed Celexa and within days of starting it felt euphoric. Within a couple of weeks, I felt depressed again so we increased the dose. Within a few days, I felt good again. Then the depression returned again. We increased the dose again and I started ultra-rapid cycling, sometimes a day or two between suicidal and euphoric, sometimes less. I called my pdoc in a panic, feeling out of control. We decided to stop the antidepressant and add a mood stabilizer. This lead to my diagnosis. I have since had episodes not triggered by medication, though treatment still sometimes triggers them.