There is no established causal link between the two. Cannabis is so ubiquitous that it is often the case that people with underlying psychiatric problems find it calms them and then blame cannabis for it if they get worse, because that's saving face in a twisted way.
Link is not the same as "it causes it".
Good point, you may very well be right. But seeing how that tragedy unfolded was enough to convince me at least to never consider it, just in case there is a causal effect.
In my subjective experience cannabis does tend to nudge some part of the brain into edit mode. What happens afterwords depends on the person.
For me it upended a lot of my alignment with the contemporary consensus morality. Before marijuana I had a sense that the morality wasn’t actually well foundationed, or at least it was equivalent to a religion in that respect, but my mind seemed to avoid thinking about it too much. With marijuana my mind freely went there, and I think a lot of my prior beliefs about the world and social systems ended up being altered.
I haven’t ended up with any diagnosed conditions, but it is inconvenient to have beliefs that are quite different from the societal default, even though in my case I do believe that my way of seeing morality is significantly more accurate on a technical basis than the consensus view. And I suspect this wouldn’t have happened without any marijuana.
I can definitely see how someone with a less analytically oriented mindset could end up going off in weird directions and writing that as a legitimate belief while in edit mode.
We definitely need studies to properly characterize what exactly this edit mode is, but I am not too skeptical about there being some kind of causal link between marijuana and going off the rails mentally, in some individuals and in some environmental conditions.