However much they suffered before that point, and whether they would go through it again to survive, are not relevant points to whether they should be glad that they didn't die. They're sunk costs.
Subtle distinction: A person's being glad that they are currently alive is not the same thing as their being better off, in total, by not having died at an earlier point X. This is relevant because the central argument for non-consensual suicide intervention is pointing out the former as evidence for the latter - incorrectly, I think. From the perspective of imminent suicide and its possible prevention, the intermittent suffering before eventual (potential) recovery is not a sunk cost yet!
I never said in the first place that most people who survived suicide are better off than they would be if they had died at an earlier point. This is a different question, but also one that people in suicidally depressive states are particularly unqualified to answer.
That said, I think it's entirely appropriate to regard the former as evidence for the latter. If self reporting that one's life has seemed worth living is not evidence that will sway one in favor of thinking that the person was better off alive than dead, what would be?
Last month, two people far at the periphery of my social circles have threatened suicide. Seems like a sign for me to learn some ledge-fu.
I reviewed the stuff I'd learned back in high school ("Listen." "Be supportive." "Don't argue." "Etc etc etc.") I have trouble believing that this would work outside of movieland, especially on strangers. More so, in person I'm an awkward, fidgeting introvert---the impact of everything I say is thus diminished, and I sound very insincere or clinical, like I'm following a bad movie script, when I say anything like, "You are not alone in this. I’m here for you." or "How can I best support you right now?" I doubt that this would sound any better in writing.
I suppose I could split my question into two related ones: what would you say to a person threatening to commit suicide, 1. in person, and 2. in an email?
I'm looking for out-of-the-box ideas that don't rely on charisma or compassion shining through. Personally, if I ever need to talk myself out of suicidal thoughts, I apply the "bum comparison principle": if my life is so crummy that I'm willing to commit suicide, then I should be willing to just walk out on everything I value and drift off in a random direction, survive by dine-and-dashing out of cheap restaurants and wash dishes if I get caught, maybe take odd jobs or hitchhike or gather roots and berries or blog from public libraries. I don't see this possibility in a negative light, and yet I still haven't done it. To me, it means that however bad my life may seem, I'm still too attached to it to walk out; therefore, suicide isn't on the menu.
People have different reasons to want suicide, and I understand that what works for me with my first world problems probably won't work for a person who is in too much physical pain from an incurable disease. To the best of my knowledge, the two people I mentioned earlier are both unskilled laborers who had lost their jobs, one of them so long ago that he's no longer eligible for unemployment benefits. I don't think I'll meet these particular people again, but I'd appreciate everyone's thoughts on what I could've said if my brain hadn't frozen.