I started getting depressed around 13. I had pretty solid depression for a long time. Even psychotic depression (I saw this shadow thing that would attack me when I closed my eyes/looked away; I also saw people morph into monsters and attack me). I don't recall any mania symptoms in my adolescence but I was dx'ed bipolar at 18. I didn't believe them because I didn't know about mixed episodes so I thought you had to be happy to be manic. I didn't have a euphoric manic episode until I was 25. Now I'm thirty.