When i've had (major/acute, or MDD) depression, it seemed to have an a strong element of "unreality" to it, like derealization??. I felt the most alone ever in those times - total complete absolute isolation/loneliness. Nothing was "familiar", not even "i" existed; absolutely everything was all new & foreign. It's like being born again as a baby, & thrown into the world all alone with zero support structure (mother, family, comforts, etc)
This reminds me of a passage in the play Woyzeck:
Once upon a time there was a poor child with no
father and no mother, everything was dead, and no one was left
in the whole world. Everything was dead, and it went and searched
day and night. And since nobody was left on the earth, it wanted
to go up to the heavens, and the moon was looking at it so friendly,
and when it finally got to the moon, the moon was a piece of
rotten wood and then it went to the sun and when it got there, the
sun was a wilted sunflower and when it got to the stars, they were
little golden flies stuck up there like the shrike sticks 'em on the
blackthorn and when it wanted to go back down to the earth, the
earth was an overturned pot and was all alone and it sat down and
cried and there it sits to this day, all alone.
