Good question.
I have been to a few dozen Grateful Dead Shows.
I have seen my share of bad trips. It was almost one per show in the 80’s and 90’s.
I also went to college at one of our state schools. I would never admit that it was a party college. I saw one or two people get pretty messed up from acid. One guy was having mental health issues and took acid often. It triggered his other issues in a bad way. He left school. Rumors said he was no Longer able to function for years.