When I was in grad school in a psych related field I admitted to a professor I had depression. I wasn't diagnosed with bipolar yet and was not visibly symptomatic even to people who knew me well. I was treated badly by certain faculty from then on, including being discouraged from making more difficult decisions with my research project than most of my classmates despite having one of the highest grade point averages in the class. It was not good and I was pretty miserable for the last year of my training. I can't imagine if I had told them I had bipolar.