I'm in the UK and, as far as I'm aware, they don't stick you on psychiatric wards for suicide attempts, or telling people you're going to etc etc. I think a lot depends on your demeanour really.
In fact, after discussions with family and my closest friends regarding my desire for self deliverance, they made me agree that before I settled on that, I would have to try every means of recovery first. One of those entailed calling my GP, who, because of the certainty with which I expressed my suicidality and the fact that I assured I would be using a reliable method, he put me in touch with what is known as a "crisis team" at the local mental health hospital. I went, told them the full facts of my intentions, how I've been feeling over the last many years, the culmination of thoughts, the philosophical reasons I have as well. They noted it all down, a psychiatrist came up with a course of medication to start with, I was given appointments to commence with one of their psychologists/counsellors and that was it. They didn't lock me up, drug me, or do anything else. I just went home, and we went from there.
I think here in the U.K. that only tends to happen if you're a danger to others as well. For example, one guy I spoke to in there whilst I was waiting (I was there most of the day), who had been there on a residential for a while, not for the first time either, was there because he was a pyromaniac and attempted to burn his house down. So, he was in there receiving treatment, but even he sounded fine. In fact, they all did. By that I mean that none of them sounded like they were being drugged heavily or tied down etc etc. Though I'm sure it happens if they kick off and get aggressive.
He was actually quite funny. I had a four can pack of zero coke on me and he boldly asked if he could have one please? I gave him one and he disappeared, only to come back 10 minutes later, placed the can next to me and went "can I have one of the others, there's nothing in this one?" - I looked at it, it was unopened. I said "you didn't drink it" and he again insisted "yeah there's nothing in it" then picked it up and turned it around and went to me "see, no sugar, no caffeine, no artificial flavourings...there's nothing in it" at which point he just grinned at me. What a nice bloke. I wonder if he's still in there