That doesn't work.

Staying alive for others while you don't want to live only makes matters worse.

Live because you want to, not because of what other people want.

If you have loved ones, that suggestion can work. If you know your (x) loves you, then you think about the pain they will feel when you're gone it can sway your thoughts.

Or it could just add the the guilt that a person feels and make suicide more likely.

We know that telling someone with a phobia "don't be scared of that thing" doesn't work.

Why do we think that merely saying "think of your family. They love you" will be effective?

It can work, at least for some time. And that time will often be enough to get them past the immediate crisis.

Thinking of family and friends may be related to the distress that our friend finds unbearable.

I've been suicidal. Thinking of friends and family helps keep me alive. But everyone's not like me.