A few years later, I got really depressed after a party and, on my way home, I stopped in a bridge, looking to the river and thinking. I knew I would never have the courage to jump, but I stood there. Then, from the other side of the bridge, came an old crazy friend, he was really drunk and hugged me real hard, leaving me with the stench of cachaça (brazilian rum). He kept going and I went home.
I never had any suicidal thought after that. On contrary, sometimes I feel that I now am "immune" to that kind of thing. Even if I feel depressed, it all goes away after a good night sleep. And I even became a person that is really good at talking to people with suicidal thoughts. I'm 24 now and, in the last five years, I've had a few friends come to me saying they were thinking about killing themselves and I somehow made them feel better.
I think that the most important thing when talking to people about this is: never say "don't to it". I usually say: "it's up to you, but.. have you considered this and that?" If you just tell them no to do it, they will ignore you, because they will think you don't understand their problems. And they are probably right about that.