It seems pretty delusional to just say these people would have spontaneously lost their minds even if they didn't do extremely powerful mind altering drugs.
It seems pretty delusional to make conclusions when you don't even know if they really took LSD or something sold as LSD, but actually dangerous, and are missing basically all other important data other than "they took something and then became crazy", while the then in the sentence means "after that", as in time, not "because of that".