It's a Funny Farm/Nut House/Loony Bin
Depression is poorly understood, and this extends to treatment. People conjure images of white rooms with padded walls, sadistic doctors conducting dubious experiments and lobotomized patients slobbering senselessly. I'm sure such places exist somewhere, but the truth is that most mental health facilities are just like any other medical facility. They're (mostly) sterile and orderly. Food comes round at regular intervals, nurses administer scheduled medications, and doctors speak with you briefly in the mornings.
What's different about being hospitalized for a mental issue, though, is that socialization is often a key part of treatment so unlike recovering from a physical malady, you're encouraged to leave your room and be around other patients. It's true that some patients don't really want to get help, but for the most part I found all of us at a point where we just wanted better for ourselves, and for our loved ones. I won't lie: a couple of patients made me uneasy, but on the whole I found myself in the company of people like myself who had simply become overwhelmed by life and needed help.
There's really nothing else as important as this. You must be honest with everyone: yourself, the medical staff, other patients or anyone else with whom you interact. You need to be honest about your state of mind. Some patients simply wished to get out of the hospital, and what we all said to one another was, "Don't leave if you're not ready." It's tempting to just want to get home, particularly if you feel like the only thing that you can do positive for yourself is to re-engage your life, but it's awfully easy to set yourself up for failure that way. Better to take some more time and reenter the world a healthy (or at least, healthier) person than to come out too soon.
The medical staff, of course, relies on your honesty to ensure that you receive proper care. If something doesn't seem to be working right, they can only make adjustments if you inform them. There's nothing to be gained by "telling them what they want to hear." They don't really "want to hear" anything (other than to be addressed respectfully, of course). In my experience, the physicians and nurses who were the most attentive were the ones that I saw being engaged by patients. People respond to other people, and it's to your advantage to invite the medical staff to respond to you. (Note: don't abuse this just for attention. There are other patients who need their attention, too.)
In group settings, honesty is paramount. You may be surrounded by people whose stories sound much worse than your own, and you may feel tempted to not want to share what led you to treatment. Or maybe you'll feel the need to embellish, and upgrade your "I lost my job" to "I was in the Peace Corps and my unit was overrun by brutal revolutionaries" just to feel like your reason for being there is "legitimate." Don't. It's okay that you haven't endured the same misery as other patients. It doesn't make your need for help any less real. Patients can spot liars among themselves, so don't bother. Just be honest. Several times I found myself sharing something that seemed trivial relative to what others had experience, but it resonated with them all the same. I wouldn't have had those moments of connection if I had tried to make more out of my experiences than they really had been.
"Haven't You Ever Heard of the Healing Power of Laughter?"
The Joker nailed this one. During my stay, there were lots of very intimate, heart-wrenching discussions that led to tears. Several times, even I just stared with no idea what to say to someone else. But I also found that most patients wanted to laugh. It made it easier to be honest with one another--and hence, ourselves. Sometimes we didn't even talk about our depression or other issues that led us there, but instead just told funny anecdotes and jokes to keep a good vibe going.
I made one patient laugh till she cried when I remarked of the linens that, "They will be towels when they grow up." Another got the biggest kick out of when I said, "There's a light at the end of the tunnel, and I don't think it's the train." These aren't terribly original or brilliant gems of comedy, but they were unexpected phrases that evoked a laugh. I could feel the tension ease once someone laughed, and it was a reminder that I actually am a fairly funny guy, and that there are people out there who need to laugh. Does it sound simple and unimportant? Of course it does. But then I ask you to consider the parking garage Jerry Seinfeld bought to house his collection of expensive cars. He paid for all that because he could make people laugh.
Cast the Movie
It's a little thing, but I found a side diversion that amused me (and some of the other patients) was to look around and think of who would play us in the movie version of all this. I didn't cast everyone, but for starters I would need Rob Lowe as a counselor, Judy Greer as a nurse and Willem Dafoe as a patient. These kinds of little games gave us something to think and talk about that helped place our hospitalization in a different context from being the embarrassing, big, bad place we went into it thinking it would be.
Talk with Other Patients
In my advice about forming a support network, I insisted that to have a friend, you need to be a friend and that's just as true inside the hospital setting as outside. The patients who seemed to feel they made the most progress were the ones who socialized and talked with other patients. We couldn't fix one another, and there were no expectations that we could or would. Rather, it was important just to have those kinds of intimate, soul-baring heart-to-heart conversations that we couldn't have with people outside of that setting. It's amazing what someone you've never met will tell you in that environment...and what you'll find yourself sharing with them. I think those conversations helped the people I had them with, and I know I benefited from them.
"You Should Be All Better When You Leave"
When most people see a doctor or are admitted to a hospital, they leave in better shape than they arrived, and this should be true of your treatment for mental illness as well. However, the chronic, incurable nature of mental illnesses means that you're not going to be "cured" when you leave. You should, however, be rebooted in a sense and have a plan for management of your condition that is healthier and more helpful than what you had in place before your hospitalization. It's a never-ending battle, and people around you may not understand that this isn't a one-stop end to your woes. Be honest with yourself and with them, and accept that you'll have fights with depression in the future and that's not an indication of failure on your part, or evidence that your hospitalization didn't work.
Ask Other Patients About the Grub
Last advice: ask other patients who aren't first-timers what they think of the food options. Everyone's taste is different, of course, but it can be nice to know that the hamburgers are actually pretty good and the chicken parm isn't. Never underestimate the power of having a satisfying meal!