I just discovered that Winston Churchill had bipolar disorder.  Apparently, he would referecne his condition by calling it "that black dog".

It's cool to know that one of the most respected men in all of Western history had bipolar disorder.  In fact, Anthony Stor, in his book Black Dog, Kafka's Mice, and Other Phenomena of the Human Mind, suggests that Churchill succeeded because of his disorder and not inspite of it:

"Had he been a stable and equable man, he could never have inspired
the nation. In 1940, when all the odds were against Britain, a leader
of sober judgment might well have concluded that we were finished."

Here are some sites with more info:

http://www.out-of-joint.com/page036.html

http://www.bipolar-lives.com/winston-churchill-and-manic-depression.html