From my experience, the way I see certain psychs helping is the cause an individual to go through an ego death and they seemingly unwire the brain and after the "trip" is over, your brain needs to be put back together. It is kind of like rebooting a computer when the cache is full. mental illness (that can be seen in many different forms) could essentially be undone because they are likely a damaged neural pathway due to trauma. After the ride is over I found myself having to do things like relearning how to see the world around me and how to walk again. It was almost like dismantling the entire brain and putting it back together as it was supposed to be put together.