I believe there was a show called Kentucky Ayahuasca on VICE TV about a healing center using ayahuasca. I wasn't a fan on his methodology but he wasn't treating someone with minor issues, these were people with deep drug addiction and heavy past trauma. The first night he would dose everyone about what I would be comfortable with, just to get them used to it, the second night these people were dosed pretty heavily as in straight to Level 5 and then given more if/when they asked for it. For some it worked well, for the few it didn't their negative experience didn't last past the actual trip.
That's the cool thing about psychedelics is that for most people it's a positive experience they carry for life, for those few that have a bad experience it rarely extends beyond the trip itself. Those people don't dwell on having a bad trip for the rest of their lives, they just forget about it and move on. Also the people that tend to have a bad trip are usually people who can't face what they may have buried inside which cases the bad trip. You have to learn to deal with your demons if you plan to take the ride.
