Unholy Ghost - Google Book Search: includes "One Cheer For Melancholy" by Susanna Kaysen 'writing about depression for the first time since Girl, Interupted' p38-43, and this from last p.43:

The worst thing about depression -- the thing that makes people phobic about it -- is that it's a foretaste of death. It's a trip to the country of nothingness. Reality loses its substance and become ghostly, transparent, unbelievable. phantom. (Melville)

When I'm feeling good, I sometimes think of feeling depressed, when what I see has a shimmer of not-thereness and what I feel has a slippery way of falling off after a minute, so that I can't sustain the sensation of being alive. But it's far away at that moment -- as far as vivacity is when I'm depressed.
as far away as health. (S Plath) .. as _ as and as _ as alone (maggie and milly and molly and may). and awoke far on ..

I know they are both real. It is a world but there's another.

. . .
"Last night I dreamt I was in the labyrinth And woke far on. I did not know the place." --Edwin Muir
“Oh these deceits are strong almost as life, / Last night I dreamt I was in the labyrinth, / And woke far on. I did not know the place.”
"It is a world, perhaps; but there’s another."
Muir you wrote the poem most mine about this did you it is a world but yes okay yes there is another.

Since I emerged that day from the labyrinth,
Dazed with the tall and echoing passages,
The swift recoils, so many I almost feared
I’d meet myself returning at some smooth corner,
Myself or my ghost, for all there was unreal
After the straw ceased rustling and the bull
Lay dead upon the straw and I remained…

I could not live if this were not illusion.
It is a world, perhaps; but there’s another.
For once in a dream or trance I saw the gods
Each sitting on the top of his mountain-isle,
While down below the little ships sailed by…

That was the real world; I have touched it once,
And now shall know it always. But the lie,
The maze, the wild-wood waste of falsehood, roads
That run and run and never reach an end,
Embowered in error – I’d be prisoned there
But that my soul has birdwings to fly free.

Oh these deceits are strong almost as life.
Last night I dreamt I was in the labyrinth,
And woke far on. I did not know the place.

That was the real world; I have touched it once