Suicide is many reasons in one word, I feel suicude is only a matter of someone facing depression or someone whom has too much angry built up inside and not letting someone in mental to help them, Or someone may not express their emotions in ways they may need to.
Even though everyone is human and we make mistakes, some can't be taken back, Yes it is bad and it is a sin but however who are we to judge on things that others feel and we don't and never have experience, everyone has their own way of dealing with thing but however we can only lend a hand to help those who want our help.