Just had a little google and found this study that says the aversive effects of THC are perhaps down to the kappa opioid system (just rats though):
This is a theory that has been believed by a few people for some time. Kappa opioid receptors (KOR's) are upregulated in trauma and also activated by salvia divinorum. When activated they cause people to have out of body experiences, believing they are a piece of furniture and having scary memories and fears come up (no fun by the sounds of it!).. but people also have incredible experiences so it is a very odd drug, some absolutely love it, others have it and say they will NEVER take it again. But of all the drugs out there, if I were to pick one that mimics DPD symptoms it would be this- so the theory of upregulated KOR's being related to DPD fits.
I have found studies before that associate THC/CBD with the kappa system. I have tried CBD oil to some benefit but you need HUGE doses really that just aren't financially attainable at the minute.
I am trying salvia divinorum in sensible, small, medicinal doses at the moment ( I am not recommending anybody else try this! ). It is high risk, but as I say I am not 'tripping' on this stuff. The theory is that salvinorin A is a kappa agonist, that will then down regulate receptors. I chew it and do not some it. I have to say that it seems to be having a really positive effect. Things really appear vividly colourful for a few days after and more 3d.. I have a plant and can't take a lot at the moment sadly anyway. I feel I need a slightly bigger dose than what I get now.. I would want to take enough to start to feel the effects and then stop.
P.s. I liken my DPD to 'being high all the time'... the problem is I didn't know that this feeling isn't the normal 'being high' feeling as everybody else has