The Internal Family Systems Model: The Freeway Onramp Out of CPTSD > BPD Hell?

In my experience over the past 15 years or so, pretty much everyone with CPTSD-induced BPD who gets into the Internal Family Systems Model when they're in the third or fourth of the five stages of psychotherapeutic recovery figures they've Seen The Light on the Road to the Promised Land.

Small Children learn how to Split into Parts because they NEED to. The IFSM "parts" are the result of that splitting. (As very clearly described in Richard Schwartz's book, the parts are the "exiles," the "protectors" (including the "managers" and "firefighters," which are roughly analogous to the "victims," the "rescuers" and the "persecutors" on Stephen Karpman's much earlier Karpman Drama Triangle.)

Over time one dis-covers all kinds of IFSM "critters" running around in their heads, including various inner children of different ages. See, for example, Three Definitions of “Splitting” in not-moses’s reply to the OP on that Reddit thread, and Is BPD a Dissociative Splitting between "Parts" that are "Inner 2-Year-Olds" vs. "Inner 13-Year-Olds?"

But the "parts" can be thought constructs well beyond dysfunctional inner children and parents, as well as functional inner adults. My personal faves are...

The three at the corners of the Karpman Drama Triangle as the resemble Schwartz's later iterations of them, as well as...

The Four Types of BPD (because virtually everyone with BPD caroms from one of those types to at least one of the other three), and...

The I's & The Eye's: Three States of Cognitive Consciousness.

Building the "Third Eye" (see above) with Choiceless Awareness for Emotion Processing on the platform of A 21st Century Recovery Program for Someone with Untreated Childhood Trauma has proven to be the paving on the Freeway Out of Hell for me, at least. See also Dissociation, Memory Retrieval, "Resociation" & Reprocessing.

Resources & References

Parallel-Distinct Structures of Internal World and External Reality: Disavowing and Re-Claiming the Self-Identity in the Aftermath of Trauma-Generated Dissociation

Separating Fact from Fiction: An Empirical Examination of Six Myths About Dissociative Identity Disorder

Van der Hart's Theory of Structural Dissociation

Earley, Farmer, Friel & Friel, Harris & Whitfield in Section One; and Fisher, Gibson, Greene, Kluft, Lynn & Rhue, Puttnam, Schwartz, Van der Hart, and Van der Kolk in Section Two of A CPTSD Library