IFS and dissociative parts

“Everyone has parts” can land badly

IFS starts from the idea that every mind contains parts. It calls them subpersonalities and says they may be experienced through thoughts, feelings, sensations, images, or other inner experiences.¹

For someone with DID, “everyone has parts” may sound like missing time and loss of control are just ordinary inner conflict. Joanne Twombly, an IFS-certified therapist who specializes in complex trauma and dissociation, has heard this from clients. She says it is confusing that they talk about us all being multiples.² Some found the comparison insulting because other people do not live with the same pain or barriers between states.²

A work-self and a home-self usually share the same memory and personal history. With a dissociative part, an action may feel as though somebody else chose it, or a memory may be unavailable until another state is present. ESTD describes dissociative parts as having firmer boundaries and, in many cases, a first-person perspective of their own.³

Some people know a state belongs to them while it still feels foreign. Mosquera gives a common example: I know these parts are me, but they don’t feel like me.⁴ A therapist hearing this needs to ask what else changes. Does the person lose time or control when that state is present?

When standard IFS falls short

Twombly likes IFS and uses it in her own practice. She also remembers being taught that coping skills were unnecessary because clients already had what they needed. Her answer now is blunt: But it didn't really work with this population.²

Twombly asks therapists to look at the week after a session. If someone leaves therapy less able to cope, or starts needing much more help between appointments, the pace may be too fast. Coping skills may need to come before more traumatic material.²

A therapist's excitement can be frightening too. Twombly says that when secret parts once helped someone survive, an eager plan to approach them may feel profoundly scary.² ISSTD warns that calling identity states forward before the person is ready can destabilize treatment. It also warns against encouraging states to become more separate or elaborate.⁵

The therapist's language matters

In a lived-experience essay, a therapist writing under the name JEREMICALA says that some parts resent the idea that they aren’t ‘real’ or valid⁶ when compared with a supposed “core” part. Other parts had been spoken about as blocks and defenses instead of being heard.⁶

The problem starts when a therapist insists on the model's language after the client has said it doesn't fit. ESTD recommends starting with the client's own words. If “parts” makes the person uncomfortable, the therapist should stop using it.⁴

Twenty-seven studies, one DID case

A 2025 scoping review found 27 peer-reviewed IFS studies. Seventeen were case studies and two were randomized trials. DID appeared in one case study.⁷

That's nowhere near enough to know how people with DID tend to respond to IFS. Therapists have mostly had to draw on specialist experience and the wider DID treatment literature.²⁵

Ask an IFS therapist what they change when a client has amnesia or becomes less stable between sessions. You could mention an identity state that wants no contact, or a week that becomes difficult after therapy, and ask what they would do next. Listen for an answer about pace and coping outside the session.²⁵ See where IFS fits within the broader treatment overview.

Footnotes

1. IFS Institute. (n.d.). The Internal Family Systems model outline. Sections I and III: Basic assumptions; Parts. The IFS model treats parts as subpersonalities within a naturally multiple mind and describes how they may be experienced. ↩

2. Twombly, J. H. (2021, November 6). Trauma and dissociation informed IFS [Podcast interview transcript]. IFS Talks. pp. 2-4 and 6-8. Clinical commentary on adapting IFS for complex dissociation, including risks of overwhelm, destabilization, premature work with hidden identity states, insufficient coping skills, and poorly paced trauma work. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

3. Mosquera, D. (2023, July 1). What are dissociative parts and how or when to introduce 'parts' language? European Society for Trauma and Dissociation. Sections: What are dissociative parts?; How to distinguish dissociative parts from ego states?. Clinical distinctions between ego states and dissociative parts, including boundaries, autobiography, autonomy, and first-person perspective. ↩

4. Mosquera, D. (2023, July 1). What are dissociative parts and how or when to introduce 'parts' language? European Society for Trauma and Dissociation. Sections: How to distinguish dissociative parts from ego states?; When and when not to use 'parts' language?. Examples of experiences that fall between ordinary ego states and more divided dissociative parts, along with guidance to follow the client's language. ↩ ↩²

5. International Society for the Study of Trauma and Dissociation. (2011). Guidelines for treating dissociative identity disorder in adults, third revision. Journal of Trauma & Dissociation, 12(2), 115-187. pp. 133 and 140-141. Guidance against eliciting identity states before the person is ready or encouraging identity states to become more elaborated and autonomous than they already are. ↩ ↩² ↩³

6. JEREMICALA. (2024, June 24). Lived experience as a therapist with dissociative identities. Institute for Creative Mindfulness. Reflections on clinical language and parts in therapy. A therapist writing from lived experience describes how identity states can experience clinical language that treats them as less real or as obstacles. ↩ ↩²

7. Buys, M. E. (2025). Exploring the evidence for Internal Family Systems therapy: A scoping review of current research, gaps, and future directions. Clinical Psychologist, 29(3), 241-260. pp. 241-260; Results and discussion. Scoping review of 27 peer-reviewed IFS studies, most of them case studies, with DID represented at the case-study level rather than in a controlled trial. ↩