My bro has a few reasons to feel shitty, but he seems to be coping pretty well these days. It's weird though cause it's hard to tell when somebody's shit is about to hit the fan. The kid we know that hung himself was actually closer to my brother than me, they were like best friends and I was only 2 years younger so I kinda fell in with em. We saw that kid and hung out one weeknight out of the blue after not seeing or hanging with him in about 2 years(families moved apart). He was excited and happy to see us and we shot some shit about old times and said we need to hang out more. He told us how he just got dui and got fired from a car sales job, but it seemed like no big deal to him, I'll say this though he was shaking like a cokehead or something. Come to find out a few months later his bro found him hanging from the attic rafters.
I don't know your life story or even you as a person, but I just have a hard time buying the fact that anyone can be unhappy for just no reason at all. Even just teenage angst is caused by underlying things like not having control over your life at an age when you are feeling more and more self reliant, or coming to an end of your worry free life of school, or not being the child anymore and having to take some responsibility.
Small things pile up and while many people will say nothing is wrong I think it's because some reasons feel so small like they are nothing, but after piling it all on it becomes everything and when everything rubs you the wrong way then you really start to have trouble getting out of bed in the morning. I guess I just feel like depression happens more to people who are somewhat lazy, if you don't take small steps to improve the small things that are getting you down then it starts to pile on.