I heard or read too many stories similar to OP's to not warn people about the risk. I agree that percentage of people who experiences long term issues is very low, nonetheless if anybody knows that cannabis makes them paranoid/anxious/delusional etc, it's best to avoid it during psychedelic experience.

Lot of people use psychedelics as a tool for self-healing from some underlying psychological issues, so some preexisting conditions are often at play.