i know criticism of psychedelics can be a touchy subject, so i'll preface this by saying that i attribute a substantial part of my success today to the things i learned about myself through them. basically, your mileage may vary.

psychedelics have the ability to activate dormant mental illness that can be very difficult to triage and therapy out of someone's life. it might be anecdotal, but i've seen a few people bring things out of trips that have been hugely detrimental to the rest of their lives thus far (20+ years since it happened)