It sounds like your friend had a predilection for psychosis. I feel like the nice things about psychedelics is that they don't alter my processing too much (as compared with other drugs), moreso they just give me different 'inputs' into my senses / experiences, and then I process those.
> It sounds like your friend had a predilection for psychosis.
No prior history of any mental illness in him nor any of his family.
This is a common excuse: Blame some hidden susceptibility, not the drug. It doesn’t matter what it was, though. The drug caused it and there were no warning signs. Fine before the drug. Not fine after the drug.