I’m speaking more personally/anecdotally but it can really shift things around from a high 2nd plateau - 4th on. I haven’t done a 4th plateau cuz it scares the fuck out of me but there you have it

Edit: there seems to be a lot of work being done(+ its very in vogue right now/fashionable) to use ketamine to treat depression. Ketamine is also an anaesthetic and NMDA-antagonist at supra-therapeutic doses…