In my opinion, if someone is saying they are suicidal, whether the friend/doctor thinks they are not going to actually do it, it is never appropriate to say "go ahead."

1. If they weren't going to do it, that comment might make them want to do it more.
2. Never assume a suicide threat is an empty threat. It's too big of a risk.
3. A doctor saying that, imo, would be unethical. Their job is the help, and that is not helpful at all, it hurts more than anything.
4. How would they feel if they said that, and the person did go ahead and do it? I know I would be devastated and feel guilty, like it was my fault.

Puck