I came here to write the same, and I'm replying to this comment to draw peoples' eyes to it when scanning the replies (in case it doesn't received enough upvotes to take it near the top) as I think it has a lot of value.

I'm personally fortunate to be in a good position mental health wise, but I know http://reddit.com/r/depression, http://reddit.com/r/bipolar and http://reddit.com/r/bipolarreddit have helped my close (non tech friends) a lot and they cannot recommend them highly enough.