Why would you want your brain to ravel back up? I've worked at ayahuasca retreats and know many people who do it for a living (who are many of the most grounded people I know). Using these things in a therapeutic manner is a completely different thing than using them recreationally, might as well be a different substance. I'd guess those people who "permanently changed their brain" (whatever that means) were not in a context for actually healing.