Pattern
Structural dissociation
This is the dominant model among dissociation specialists (van der Hart, Nijenhuis & Steele). Trauma divides the personality into a part that carries on with daily life and parts that stay stuck in the threat. It’s a spectrum: one split in PTSD, more in complex PTSD and some BPD, and many in DID. It’s useful because it makes symptoms make sense.
Clinical consensus