I'm late to this party but I'll jump in anyhow
I had a lot of fun writing a paper on this book (socioeconomic problems in mental health care blah blah). YES it is amazing! Talk about cool history, especially if you live around Boston. It's like a little glimpse into the secret lives of the Boston aristocrats, way better than anything "Reality TV" could throw at you. There are lots of interesting anecdotes throughout, weaved around the history of psychiatry as it happened, right at McLean. It's written like a novel and is at times hard to believe it's non-fiction! The first time I read it was in one sitting, I couldn't put it down. Definitely not a stuffy history book!
I first read that years ago only because it was about McLean, but it was so engrossing I wanted to learn more. Probably one of the reasons I'm studying mental health care now. If for some reason you end up feeling the same way, I have some suggestions! (well, many suggestions... but I won't be that annoying.)
"Mad in America" by Robert Whitaker is similar to Gracefully Insane in some ways, in that there's a somewhat narrative quality to the writing. Keep an open mind here, it's basically an attack on how medications are being used to treat schizophrenia, though the book has a great deal of interesting history as well. I wouldn't take Whitaker's word on psychopharmaceuticals as gospel, but it is beyond interesting!
For a more partisan approach, though a bit heavier on the science is a book called "A History of Psychiatry" by Edward Shorter. Like Mad in America, there is a lot of really awesome historical information, in more depth - or rather, detailing different aspects - of mental health care. If you liked the narrative of Beam's book you really might like this one, it's amazing. There is SO much information packed into this book I could probably read it a hundred times and still want more.