A blogging friend of mine recently posted about how she thinks she's finally figured out what kind of depression she has - atypical depression. Out of curiosity I started reading the Wikipedia article, to better understand what she's going through.
I was surprised to learn that there is a type of depression where you aren't sad all the time - positive events can lead to temporary improvements in mood. That "mood reactivity" has always been my experience, ever since the onset of my depression in college. Dancing, especially, always puts me in very high spirits. I mostly figured I had some form of bipolar disorder.
I am well aware of the problems of self-diagnosis, so mostly this just has me thinking thinky thoughts about what the heck might be going on inside my head.