assisted suicide vs suicide prevention

[I_am_not_mafia]

So I know there are quite a few people here who have said that they support assisted suicide for any person who no longer wants to live, so long as they are an adult. The rationale is, a person has the right to end their life for any reason if they so choose, and there should therefore be a safe and painless options for them to do so. 

For those people, my question is, do you feel then that it is not appropriate to call 911 when a friend tells you they will kill themselves, since you are preventing them from doing something they have a right to do? Do you think we should lay off the whole suicide prevention thing, and just let people choose for themselves, and not make suicide into this thing we should prevent people from doing?

If someone tells others that they want to commit suicide than it could just be a cry for help and they are in such a serious emotional state that they could end up damaging themselves and degrading the quality of their life.

If I was talking to someone who was truly suicidal because of depression, I couldn't in all honesty tell them not to. But I also appreciate that in such a case their perspective will be completely skewed and they can't currently make an informed non-emotional choice.

If the person wanted to end their life because they knew for sure that it was not going get better and only going to get worse (e.g. because of a medical diagnosis) then there is absolutely no way that I would try to convince them out of it.

We had a situation recently here in the UK a woman threw acid over her boyfriend while he was waking up. He was left in such a bad condition that he ended up choosing assisted suicide. She was then retried for manslaughter / murder (can't remember which). It would be immensely cruel of me to convince someone not to commit suicide if they were in such pain solely for the sake of my own personal feelings.