Are Internal Family Systems therapy (IFS) and Acceptance and Commitment Therapy (ACT) therapeutic cousins?

The contents of this blog are my opinions and are not the opinions of any current or former colleagues. This is not to be construed as mental health or medical advice and does not constitute a relationship with a professional therapist.

I learned about Acceptance and Commitment Therapy (ACT) when I completed my clinical internship in my last year of graduate school, which was 2019-2020. I had a graduate professor, who I quite admired, who was my site supervisor for that internship. I was practicing in-home therapy with individuals diagnosed with serious and persistent mental illness (SPMI) for my clinical placement. My professor shared her fondness for ACT, and she felt (for reasons she did not elaborate on, that I can recall now) that I would be a good fit for practicing ACT. Her assessment turned out to be correct; most of my current clinical interests revolve around therapies that help us become more open and curious towards our inner experiences. I believe Internal Family Systems therapy, Acceptance and Commitment Therapy, and psychoanalysis share a common thread in this regard. Arguably, a lot of other modalities do as well (example: Somatic Experiencing), but I do not have the dearth of knowledge about them to make the same claim.

I purchased and read Russ Harris, M.D.’s book The Happiness Trap around that time (in the late winter of 2019.) Harris’ book appears to be directed towards laypeople and not clinicians, but I found it to be professionally (and personally) helpful. I recall practicing ACT skills on myself when I read through it, and utilizing those interventions in many of my earliest sessions as a clinician. I consider ACT to be a skill-based approach to psychotherapeutic treatment, which is useful when we are willing to practice its six core processes.

Fast forwarding five and a half years, I have taken numerous trainings in Internal Family Systems therapy. Lately, I have been wondering about the relationship between IFS and ACT. Practitioners of either discipline might staunchly disagree with me (my professional email is attached to my website if anyone wants to engage in a lively discussion about this), but I feel they can be closely related. I am fond of calling them “cousins.”

The Happiness Trap describes ACT as having six core processes.

1.     De-fusion (or cognitive de-fusion)

2.     Expansion

3.     Contact with the present moment

4.     The Observing Self

5.     Value clarification

6.     Committed action

De-fusion (or cognitive de-fusion) is the practice of noticing (or, attempting to notice) your thoughts without judgment. “I notice I am thinking [x]”, “there is that same story [x] again”, thanking your mind, or even just noticing and naming “thinking”, are all common de-fusion strategies. If we swap out “thoughts” with “parts,” this is not dissimilar from what we practice in IFS sessions, and what we might practice between our IFS sessions. As I discussed in my previous blog post, I try to remain curious about which part of us is doing the noticing (Self? A Self-like part? A thinker, or critic? How do we feel or react when we notice those thoughts? Curiously? Overwhelmed? With rage? Do we align exactly with what they are saying to us?)

Expansion is the practice of accepting and allowing (or attempting to accept and allow) our feelings. A common prompt here is to “observe, acknowledge, breathe, create space, and track.” The thought is when our tense or stuck feelings are given room to ‘breathe’, physiologically, they can become unstuck, process, and move on. A common prompt in a session of IFS is “would that part be willing to give you more space than it is giving you now?”

“Mindfulness” and “meditation” are both therapy buzz-words with thousands of different definitions. Both tend to support contact with the present moment. I recall reading in Richard Schwartz’s book No Bad Parts that he describes Internal Family Systems as “mindfulness plus,” basically mindfulness with the added component of engagement or interaction.

I was fortunate, in December 2023, to see ACT’s inventor Stephen Hayes, PhD give a presentation at a psychotherapy networking and training event in Anaheim, California. He excitedly shared his recent research findings. I also recall him speaking about de-fusion. Hayes explained that as we successfully begin to differentiate ourselves from our constantly running stream of consciousness, he said (and this is nearly verbatim) “there is this other version of you, this spiritual version of you, behind your eyes.” I believe he was talking about what ACT describes as “the observing Self;” IFS centers around the notion that we all have a non-part part of ourselves that Schwartz coined the Self, our inner openness, gratitude, compassion, curiosity, and so on. It is worth noting here that the psychoanalyst Donald Winnicott historically coined a term "false self", which “refers to a defensive persona developed to protect the vulnerable ‘true self,’ often shaped by early relationships and societal expectations.”

There is a bit more divergence between these two models with regards to value clarification and taking committed action. Common conversations in therapy offices often revolve around “core values.” ACT suggests that we connect to our core values and take committed action towards them, in other words it is important for us to “do what matters.” I believe IFS is helpful at clarifying our inner values; I believe that we can have parts which have differing sets of values (i.e. “a part of me thinks I should eat better and become healthier for my children, but another part of me is really interested in just turning the week off and eating a whole large Papa John’s pizza on Friday.”) I do not practice much behavioral therapy. I am not suggesting behavioral therapists are bad or awful people, I imagine they are (usually) good and helpful people, but I believe it is important to pay attention to our inner forces which might ‘keep their foot on the brake.’ Is it possible to negotiate with those forces, or obtain their permission which might allow us to take steps towards doing what matters to us?

I recently read an article which also supports the use of and intermingling of both modalities. I’ve learned that renowned therapists including Janina Fisher, PhD, and the aforementioned Harris, teach their clients to call out various ‘parts’ when they notice them. I believe that using IFS and ACT in coordination can help achieve the goals both models strive for, which include increased psychological flexibility and the processing of our traumatic and shameful material (which is another great therapy buzz-word, “healing;” Bruce Ecker describes this process as “memory consolidation”.)

Final note: I recently finished reading Paul Williams’ book Invasive Objects: Minds Under Siege. I found it to be an exhilarating read, and intended to create a blog entry about it. The blog entry proved to be much less exhilarating than the text, which led me down the ACT and IFS rabbit hole afterwards. It might see the light of day at some point in the future, or I might give those parts of myself permission to let it go. I am learning that attachment theory appears to be a newer version of object relations.