Anti-gravity spiral.

Life You've probably read this already (it's the first post I've seen at blogpost to reach five thousand comments) but in words and pictures and ironically in a very funny but also very tragic was, Allie Brosh explains what it's like to be depressed. Not just down, but medically depressed:

"The beginning of my depression had been nothing but feelings, so the emotional deadening that followed was a welcome relief. I had always wanted to not give a fuck about anything. I viewed feelings as a weakness — annoying obstacles on my quest for total power over myself. And I finally didn't have to feel them anymore.

"But my experiences slowly flattened and blended together until it became obvious that there's a huge difference between not giving a fuck and not being able to give a fuck. Cognitively, you might know that different things are happening to you, but they don't feel very different."

On the basis of this, I'm probably on the borderline. Which is either really worrying or entirely normal.  Her first attempt is here.