Not the parent, but my understanding is that the effects have a lot to do with the brain entering a short term state of neuroplasticity at a level that is not normally experienced in adulthood.
The result being that processing emotions and making key realizations actually “stick”. It’s possible for example as someone who suffers from PTSD to realize that it’s no longer necessary to be on high alert, but the body is anyway.
I’m also no expert so take this with a grain of salt, but I think it’s less of a defragmentation and more of an increase in pliability that leads to lasting changes.
This is one of the reasons that Psylocibin-assisted therapy is showing such promising results. The brain entering that state unguided may or may not lead to good results. But when a trained therapist is involved, outcomes improve.
This study would certainly seem to indicate that this is at least true in some form — the study shows that parts of the brain that are typically very well correlated with each other (one fires then the other fires, or they fire together) come uncoupled from each other under the influence of psilocybin.
I'm not sure it could be correctly stated in the gross sense as "jumbling it up and making it re-build," but there certainly is a shift in how the brain's components work together for the duration of the drug's effects, per this study.
I must ask, is this based on scientific evidence?