Valerie Aurora wrote an extremely good essay addressing what to do in this situation, and who is responsible for doing it. It starts by explaining what's wrong with telling suicidal people to "reach out and talk to a friend," as though this would save their lives and not merely be an added burden, and goes on to address things like sending the police to intervene. It argues
that we, as as [sp] society, should take more responsibility for making people’s lives bearable, and focus on supporting more concrete ways to prevent suicide, like helping people contact professional help, supporting research and treatment of depression, and fighting for social justice.
For instance, in the case of my parents of origin apparently calling a United Way suicide hotline which in turn sent police officers to my door -- as described in this somewhat visceral entry which I've now made public -- more helpful things they could have done to diminish my risk of suicide would have been:
Encourage me to seek mental health treatment when I began having "emotional problems," about 12 years ago while we were living in Utah, from a licensed therapist who places my well-being ahead of adherence to Mormon doctrine.
Read the Mormon version of Supportive Families, Healthy Children, a booklet published by the Family Acceptance Project. It explains how treating me the way they did when I came out to them as transgender increased my risk of suicide significantly, and shows how to relate to LGBT children in a way that the data show better upholds Mormon teachings on the importance of families.
Treat my increasing unwellness and depression while living with them as our problem, not my problem, with the goal of helping me become healthy and not self-loathing (and gender dysphoric). Instead of communicating to me in a number of ways, and bringing me to a church which taught me explicitly, that if I can't live a sufficiently Mormon-y life it's better if I killed myself.
Reach out to me with the intent of making restitution for the "mistakes" they admit to making and the damage they've already done. Such as my father of origin beating me as a young child, terrorizing me once I became sexually mature, and then breaking his agreement to co-sign a long-term lease and effectively raising my rent by $100 a month once I came out to him.
(Although I haven't counted, that last one is pretty easy to put a price tag on, and it is looming over every interaction or potential interaction with them. Why should I even talk to them when they directly caused me $XXX in damage, and show no sign of wanting to make up for it?)
Anyway, while that's all specific to my situation you can see how it applies to many other suicidal persons or marginalized groups of people. Instead of giving unhelpful advice, or using force to intervene, if you're concerned about someone you should educate yourself about their situation, and then (personally or as a society) take pressure off of them so that they can regain their emotional health. This applies doubly if you or your society are responsible for the state someone's in, like with young persons, victims of abuse, persons of colour, indigenous persons, poor persons, and gender / sexuality / species / romantic / religious minorities.
Whose choice is it, anyway?
The way things are set up right now, in the quasi-theocratic settler state that I live in, suicide is basically a crime, no matter how hellish your life is. The only way that makes sense is if your life isn't your own.
As Valerie says:
I want to put in a word for suicide as a legitimate, reasonable option in some cases. If you can’t imagine a situation in which killing yourself seems like the best option, you simply haven’t suffered very much. Suicide is, in a sense, the last form of protest against suffering that is too strong to make life worth living. Sometimes that suffering is purely organic – there’s something wrong with your body and it’s caused by nothing related to society. But sometimes, suicide is a protest against being forced to function and give support to a society that is so unfair and unequal that it’s not worth staying alive.
If you really want to help, don’t do things because they help salve your personal feelings of loss and guilt, do things that lessen the suffering and illness that cause suicide.
She gives a list of these things towards the end of her essay.
Thank you to everyone reading here who has helped with those things.