For those of you who don't read the New York Review of Books regularly the current issue online has a great piece by Oliver Sacks on "bipolar disorder." The books under review all sound fascinating, too. I mean, it's not always true that the book that gets a great review written about it is a book you would want to read. But these are.
On the subject of mental illness, via Metafilter I got to, of all things, a schizophrenia simulator. It gives you the experience of being schizophrenic and going to the drugstore to get a refill after losing your meds a week earlier. You should really try it out. It's basically just a video. I recommend using headphones with it. It's really quite creepy.
I've known a couple of people who suffered from it, and one person who developed it almost under my eyes, and saw his parents just stricken with full-on grief. It was intense to know their son (who was about 19 at the time) as this perfectly nice, thoughtful, studious and gentle, rational being, and then to find him just tormented by these voices in his head. It was hard to believe what he said was happening, or to appreciate how deeply it was affecting him. You could see that he was suffering, but it was also hard to understand that he couldn't just switch it off the way you switch off distracting thoughts that beset you at one time another throughout the day. I remember getting him to go for a short walk with me, and the anxiety and fear made him turn back; I understood then that the most ordinary experiences had become an exhausting struggle to reclaim himself from these creepy inner voices that just would not shut up.
If you try the simulator out, I'd be curious to know what you think of it, if anything.