I am going through a very serious bout of it now.  gah, I hate my life.

that happens to me as well. I sometimes has depressed moments when I feel fine, mood swings sucks

From what I gather, many times we take being in a slump or feeling blue as depression (not always, but a lot of times). My psychology teacher said it just may be normal to feel blue, and that in societies may just make it to be abnormal or something...I can't quite remember what she said ....Good luck and I hope you can get out of this slump/depression!