I am not the person you replied to, just another sufferer.
So, for me, depression feels very similar to what both darius and the original article were saying. It's like an erupting storm. It starts with something small -- some tiny failure which a normal person might say "okay, no biggie, I can deal with that." My problem was the multiplication. We have associative memories, and I as a depressed person immediately associated this failure with other recent failures, which associated with others, and others, until there was a deluge of connections. It feels like a literal suffocation by failure -- I mean it becomes hard to breathe and there is often an ache across my chest.
There was often a growing sense of paranoia -- that they would all find out. What they would all find out was not terribly clear, but it was something as simple as "I am useless" or "I'll never live up to any of their expectations." (If you've never suffered from depression you might even wonder why this is a bad thing -- but that sort of metanarrative doesn't happen when you're depressed because it's just obviously bad, it's rejection, and rejection is painful emotionally, and there is no reflection.)
And so each thing triggers other things, until I am just left with this deep feeling that I have failed as a human, like everyone else has this thing going for them and I simply do not, and my only normalcy comes from the lucky fact that most of them are not paying any attention to me, which is also sad in its own way.
I live a much less stressful life now, and that helps. I try not to commit myself to any futures -- I tell people that I don't make plans per se but only resolves, so that I am sure of the direction that I'm sailing, but not what I will find. That helps with avoiding that seed of failure from which the storm starts.
As for the storm itself, I've found that deep breathing does more good than you'd expect, because if you're focused on your breathing then you're not associating those thoughts so much; the thoughts still swim around your head but they don't breed new ones so much, and you can kind of quietly nod at them without indulging them. This gives me a better sense of the objects around me, which actually seem to totally disappear as I disappear into myself.
But sometimes, I will confess, I feel duty-bound to be honest to my younger self. And so sometimes when those seeds start, even these days when I can cope, I do just let them expand and expand until I cry myself to sleep. I feel oddly at home there, as if this is some permanent part of myself which I'm oddly glad I haven't lost. But because this is now a choice, and it's voluntary, I no longer feel suicidal during these periods -- just awful.