Did anyone try low dosages of 3-HO-PCP?
If I take it I usually take more than 5mg with benzos and opioids, but eventually it'll work as an antidepressant in dosages at about 0.5mg - dunno, but I'll try next month.
Although Tramadol is not a dissociative IME it works great as an antidepressant. The SSRI/SNRI effects of Tramadol kicks in 15 minutes after ingestion. I prefer the liquid form. If I take Tramadol, I do it rather because of the SSRI/SNRI effects and less because it's an opioid.
There are also psychiatric clinics in the EU where patients get it off-lable as an antidepressant. So you could give it a try if it doesn't interfere with your medication. I don't like Dextromethorphan because of it's nasty side effects. Sure Tramadol has side effects too, but if you take less than 200mg at once IME you'll be fine and if you haven't tried it before maybe start with 100mg just to be safe.