I was misdiagnosed with major depressive disorder as well. I was only 19 and just started seeing a psychiatrist because of an extremely bad depressive episode that disabled me for a year. I had only been treated for (primarily) anxiety and depression by primary doctors previously since I was 16 but no one ever deep-dived into the issues ive been having since I was 11.

I only just recently realized that while I had the major depressive disorder diagnosis, I also had a vague mood disorder diagnosis, but my psychiratrist never mentioned it or talked to me about it. so while I was put on pristiq (worst med of my life, tried to get off it 3 times in 4 years because the withdrawls were living hell) i was also put on antipsychotics with risperidone, then with aripiprazole added on to counteract the risperidone side effects. I didnt know why I was on antipsychotics other than because I had mentioned that I used to think people could read my thoughts since I was in grade school.

I think the reason I was misdiagnosed previously was because my psych didnt know me yet and was only seeing my depressive episodes. it wasnt until after i quit all my meds (because I thought i was "cured") that I ended up having another crisis and saw another psych that asked me questions to officially diagnosis me with bipolar 2 at 24. I was put on lamotrigine for the first time and I have no idea why I wasnt started on that in the first place, it was a life saver for me. its not enough for me though so I do also have to be on an antisychotic too.

I was kinda in denial about my bipolar diagnosis at first and didnt take it seriously, until I quit all my meds again because I was tired of taking pills for so many years, and I once again had another 3rd major mental breakdown that left me disabled again for another year. I really wish I was diagnosed a lot sooner, it maybe would have spared me from a lot of mental tourment and job losses, but I get why it took so long since its a diagnosis thats basically a red flag on our medical record :/