Have a look at this video at around the 16 minute mark.
This is Dr. Beck (who is one of the fathers of CBT) talking to Yapko.
Beck says that the way he deals with personality disorders is he takes them back to where it all started and has them relive the experience. Then he has the mature part of them come in. He says that having them relive the experience takes the problem and makes it like molten medal once again so it can be reshaped.
This is right after he has spoken about the ineffectiveness of pounding pillows. He says that pounding doesn't work because they don't learn anything new. When you do AR with insight, they do learn new things.
Yapko, being the good Ericksonian, is of course horrified...
Simply fascinating to me that the daddy of CBT is using classic Elman/Kein/Banyan style age regression!
Go watch it, it's really worth your time.
Enjoy.
Joe