I don't know the full details, but 700M users and 1 million per a week, means up to 52M per year though I imagine a lot of them show up multiple weeks.
That being said: Those of us who grew up when the internet was still young remember alt.suicide.holiday, and when you could buy books explaining relatively painless methods on amazon. People are depressed. It's a result of the way we choose to live as a civilization. Some don't make the cut. We should start accepting that. In fact, forcing people to live on in a world that is unsuited for happiness might constitute cruel and unusual punishment.