Suicidal people haven't gotten enough love. Most suicides in adolescents occur at home. There is a genetic predisposition for suicide. Suicide happens without warning. People seem to be in better spirits following a suicidal crisis, the suicide risk is over.
Suicide strikes much more often among the very rich and the very poor.
Think about it. I think I'll kill myself. Of course not. But if you were thinking of killing yourself, you might feel relieved that someone cares enough to notice and to ask. Most people who kill themselves feel desperate and they act on that feeling.