10 days, for depression. Almost a year ago. At the time I didn't think it was Social Anxiety, but rather Asperger's Disorder. I show a lot of the signs of Asperger's, but with closer examination, Social Anxiety really makes more sense. I never had facial recognition issues, I'm kind of too sensitive/emotional/(dare I say)empathic, and overall, it's more of a personality quirk thing. ... but I digress.
It's a shock, at first. Although in my experience it might not have been as bad if I'd entered earlier in the day than after midnight when it's morose as can be. But it takes a bit to get used to; realizing you're pretty much in what they call a "mental hospital". Overall it's not that bad, you get to sleep in a bit, the breakfast's not bad, the food is... mostly not bad, it's almost like a hotel except you're not allowed to leave the floor.
Personally, my experience is a bit unique; my psych ward had two sections: An "adolescent unit" or "under 18" floor, and an "adult unit" or "18 or older floor". Just turned 18 at the time, I could only go to the latter, which I doubt helped at all. After a bit of persuading I managed to go to the former unit ("under 18"; could persuade, since I was still in high school despite being 18). Only there I made any progress, since some of the other people there were in the same age range and it's a re-assuring feeling that "I'm not the only one who's 'crazy', I'm not the only one..."
The staff aren't bad or anything (I hated my primary doctor because among the day-to-day questions, some involved sex and I hate talking about sex. You'd think he was a Freudian psychologist, except he didn't really seem to care about why I hated talking about it.), but only a few really are helpful. I don't think I had much one-on-one "therapy" there. A lot of it was checking to make sure I was "taking my meds" (they're more for medication than resolving the real problems), and did my workbook pages, which were annoying.
Then again, it was vague for me. I didn't specify anything beyond depression, thinking that aside from "some Asperger's", the social anxiety was "perfectly normal" and thus nothing I bothered to mention. Maybe if I'd brought that up things would've been different? I don't know.
Would I recommend it? If you're 18 or older, probably no, unless you're having even more serious issues where either your life or another's life is at serious risk, something along those lines.. If you're under 18? Possibly, but only if your depression is seriously in a pretty bad state; i.e., involving alcohol, drug, or self-injury addiction, really no will to ever live, etc... if only to get you standing back up before entering the real world again. I don't know, it's complicated... How bad is the state of Anxiety or state of Depression in question here?