As an ex-chonic weekend user from 2002 to 2008 (with some pauses for a few months and sometimes while on medication...) I experienced a clearer mind while under the influence of cocaine, but 95% of the time I was excessively drinking alcohol with it, thus my thoughts became somewhat clouded again.Yes it's plausible. But the point I want to make: There is, at least to my knowledge, no evidence yet, that this kappa-upregulation, that is taking in addiction, causes depersonalization. It would be a good idea to investigate if former cocaine addicts are more prone to depersonalization.
So while cocaine also helped with social anxiety (the drug induced dialogues) + made you numb to pain (I once missstepped, ripped the ligaments of my left-ankle and still partied on...) and gave short-term bursts of energy, the effect on the VISUAL abnormalities of dpd, drd (the feeling of being in a movie, behind glass and the general dissociating of reality) stayed the same.
The hangovers on Sunday where terrible, getting out of bed was a task in itself + anxiety doubled in intensity + the fact cocaine is highly addictive. I would not recommed it's use to alleviate dpd, drd.
I'm pretty sure some oxidative stress has occured, what I don't know if Kappa receptors have been affected. Maybe Elliott with two T´s or TDX can give some insights.
edit: currently on Lamotrigine 500mg/d + Prozac 60mg/d, no effect whatsoever.