You’d need to have a chemical imbalance of the brain which most commonly begins to show symptoms between the ages of 17 and 21. That’s not all though. You have to ignore the problem and how shitty you feeling on a constant basis for a minimum of one decade. Then decide you can’t live like that anymore. It’s no quality of life, you know?
Then you try 47 different medications until one, or a combination of two, three and so on work for you and then you are far more stable. I refer to this as high functioning mania, which is about where I’m at but it didn’t come without a shitload of trial and error.