Teenage suicide occurs due to a variety of factors. The main cause of teenage suicide is time. Young people who spend longer with such a chaotic emotional state are far more likely to commit suicide.
Time is the main factor. If something begins to bother someone, it starts as a mere irritation. They can put it off for a while, but eventually it begins to take over their lives. Over time, they start to lose the ability to cope. And this is when they start thinking, and attempting, suicide.