Not sure if it's the same thing, but the only thing I know about doll therapy is it being used in dementia care, which was AMAZING. We had a psychologist train us (as nursing staff) to use it therapeutically and the benefits were huge.
I've used them with a family member when she was a teenager to help with anxiety associated with a learning disability, that was super helpful too. It was just comments from members of the public which were difficult to handle...