Some time ago, I was suffering from several months of severe depression.

Out of desperation, I obtained some Ketamine. I carefully measured a dose that was somewhere between theraputic and recreational.

I had the experience of seeing myself in the third person, as a narrator: "look at him," I said about my body, "just lying there on the couch."

Time passed and I returned to my normal awareness.

There was no noticible effect on my depression. Many months later, it gradually abated.