John Piper has an excellent message about songwriter William Cowper. Cowper dealt with extreme depression, and suicidal thoughts. While this might sound like a morbid message, I assure that it is very encouraging. Listen to it here.
(I should add that I just posted this because I found it in draft form and finished it and published it. I did not know that it would go to the top of the page. I still plan to post regularly at Covered By His Hand.)