My number one trigger is music. It doesn't matter what type of mood I'm in, music can always easily change it. Whenever I'm actually feeling okay, one song can bring me way down. Sometimes it doesn't even matter what type of song it is. If it's an upbeat song, I'll be reminded of how I don't feel upbeat inside and I'll get down. If it's a love song, I'll be reminded of how alone I am and I'll get down. If it's a sad song, well that can make me get down to the point where I cry. I love music but man can it be triggering for me. My biggest trigger after that is reading about/seeing how happy other people are, especially if they're people I know. If I read somewhere about how happy someone is and/or how great their life is(which I don't think is wrong of them to talk about or anything), I'll be reminded of how unhappy I am and how shit my life is and I'll get down. Same goes for seeing people's happiness/great lives in public. Sometimes I don't even like watching certain shows/movies/YouTube videos because the happiness I see in them just gets me down. Anyway, I'm just curious what your guys' triggers are and how you deal with them and stuff.