PROZ4C, I'm not sure restricting your weed usage like that would necessarily help. Heavy weed users (in my experience) seem to forget how intense weed can be without a tolerance, and smoking as infrequently as once a month would give you no chance to build a tolerance. It's possible that whatever aspect of weed causes dissociation would therefore be experienced fully every time, whereas tolerance might actually mitigate any mental-health risks. I have no idea about the actual mechanics of this though; I may be totally wrong.
Might seem an odd point to pick over, but I was interested because your hypothesis is quite similar to the way I have consumed weed over my lifetime, though I smoked ~fortnightly. I've recently given up, for what it's worth. The mental effects I felt were simply too worrying, I was seriously fearing that I was one of those souls unfortunate enough to be biologically predisposed to schizophrenia. Having given up for a couple months now, I suppose my fear has diminished 50%, but it's still lurking, the thought that perhaps in 10 years I'll break. But none of this is about dissociative disorders OR psychedelics, so I apologize for going off-topic and using this to confess my probably hypochondriac fears.
But to echo what you've said, psychedelics don't seem to damage me like that at all. They
seem positive. I'm still taking it easy on them, though. Considering that much of their usage was concurrent with weed, I can't really claim to separate their effects.
bupropion, I would like to hear more about your experience with K against your will. The most benign way I can imagine would be you were duped into taking K as opposed to some similar drug, and then immediately informed after dosing. But I can imagine some horrific alternatives, being forcefully injected etc. If it was like this, then the stress could have done a lot of damage itself. I hope you're ok.