Man, they used a mix that included ketamine for mine, and it was amazing.
Not necessarily the being high part, though that was nice.
It was the other effects. The visual and auditory hallucinations when coming out of anaesthesia were phenomenal. I was talking to angels and I don't even believe in such things (still don't, I know it was the drugs). It was some profound shit too, some deep insights into myself, and how I interact with the world.
Which may or may not have had any relation to the biggest benefit. My depression and anxiety, and even most of my PTSD symptoms went into remission for nearly six months. I still don't know if the nature of what was playing out nectar of the drugs did it, or if the drugs changed my brain chemistry temporarily, or some mix of those, but it was a huge thing.
While all of it came back, it wasn't as severe; and having had the experience of remission makes the bad days a little easier to get through. I guess that actually makes it a permanent/long term change, now that I'm thinking about it, just not a total change. That's been back to right after I got married, which was 12ish years ago.
Ngl though, the feeling of happiness during the time after I came out of it was pretty damn nice in its own way. I was in zero pain (chronic pain sufferer) for about an hour, and every step I took felt like walking on the moon. Just free and bouncy. I babbled non stop, with my mouth full of gauze, and was singing along to everything on the CD that was in the car.
That lasted until maybe a half hour after I got home, and then the nausea hit lol. Total buzz kill, that.