Sometimes seeing other people around you succeed without really trying much, can make you feel like a ''loser'' and then feel depressed, especially if whatever you've tried to accomplish it's always been a case of ''one step forward, two steps back'' type of thing. It's even worse when bad things happen to you that are beyond your control, and then you find your parents worry about you and you don't want them to be ashamed of you, you want to be like everyone else and succeed in life and be happy.
Also having extroverts around you can trigger off depression.
Not sure if I'm saying the right thing here but I'm just stating small things that can trigger off depression. Then all the negative emotions swirl in with it; jealousy, isolation, anxiety, fear. If you experience these emotions quite frequently, then it could be some signs of depression. I've already got depression, it's f*****g horrible.
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