Tianeptine is an anti depressant prescribed in some countries outside of the US that has an extreme opiate effect when taken in extreme doses. I think the idea of finding opiate like drugs at effective doses to treat depression but skirt physical addiction is interesting, but a dangerous game indeed.
Anecdotally, ketamine has changed my life. I found a low cost clinic run by psychiatrists and get injections once a month. I don’t even care if it’s placebo effect, I’m better than I’ve been in 8 years of pharmacy-psycho therapy.