I got sent to the psycho farm for suicidal ideation once. It's not as bad as you think, if you can keep a clear head. Problems happen when you fight them or act like a psycho (like my suite mate did).
Just so you guys aren't unnecessarily scared, here's exactly what you can expect (USA only).
1) Cops come. DO NOT ARGUE. In general it's a bad life choice to argue with anyone wearing dark shades and unbuttoning the holster on his gun. If you can't immediately convince them that you're a happy harmless sane person, then just go along with it because it's easier to fool the doctors.
2) They take you to the hospital and dump you in a holding tank. No phone call. The tank has no windows and nothing you can harm yourself with, unless you're really ingenious and figure a way to kill yourself with a doorknob.
3) A nurse, and then another, and then another, comes to ask you your story. As annoying as it is, just play along. Stick to your story that you love life and this is all a big mistake. Act upbeat but don't smile too much or they may interpret that as a sign that there's something very wrong with you because who the hell smiles these days.
4) Still no phone call, nothing to drink, you're basically left alone for like 6 hours (no exaggeration). This is how they drive people insane so they can legally commit them. Be strong! Pass the time by thinking of 99 ways you can kill yourself with a doorknob.
5) They move you around a lot, a few more nurses ask you to repeat the same story you've told half a dozen times already. The whole "check in" process lasted 30 hours for me.
6) Finally they move you to the actual psycho ward. Yes!! Free cookies. Victory is almost yours. A dozen new nurses ask you your story. Resist the temptation to pin them down and asphyxiate them with free cookies, that's precisely what they WANT you to do.
7) At night you don't get a bed, you're forced to "sleep" in some stupid medical armchair contraption that is only slightly more comfortable that an economy class seat on ValuJet. But if you make friends with the pharmacy person, you might get some fun stuff to knock you out.
8) Try to ignore the echoing cries of fellow psychos who didn't have the benefit of reading this survival manual beforehand. Those people, and the ones who argue, tend to mysteriously vanish in the night.
THE PART YOU'RE ALL WAITING FOR, IN CASE MY LONG RAMBLE HASN'T BEEN ENTERTAINING ENOUGH...
9) By law they can't hold you more than 3 days unless you have demonstrated that you're a psycho. So on day 3, if you've been good and eaten all your cookies and watched all the G-rated movies playing in the dayroom (god if I have to watch Finding Nemo one more time I really will fng kill someone), then you'll finally get to see... A DOCTOR. This doctor is extremely bored with life and will only give you 8 mins of his/her time, so you better make it good. Act totally normal which means no drooling or trying to hang yourself with his necktie. He'll try to trick you by asking harmless questions like "do you ever feel like hurting yourself" but answer Noooooooo. Tell him you can't wait to go home and watch Finding Nemo. The strategy is to bore him so much that he has to let you go.
10) Go home. Kill self :)