What you seem to be after is scientific evidence. The problem is that these substances by nature cannot be double-blind trialed because blinding is impossible. So as individuals we all need to make a decision whether we would like to try them or not for ourselves and the best evidence we can ever hope to get is subjective and anecdotal. If you want to deny yourself the potential of these life changing experiences without scientific evidence then that’s your choice. In my opinion it’s your great loss too.