IFS vs. ACT: Which One’s Right for Me?

A Neurodivergent-Affirming Look at Two Powerful Therapy Models

As a therapist who spends much of my time working with OCD, I am well versed in both Exposure and Response Prevention and ICBT, methods that are highly active and effective. However, as a therapist who works mainly with multiply neurodivergent folks, I am not always working with someone who is ready to take action on OCD. They may not yet be able to decipher OCD processes from other thinking processes, or they may feel too unprotected to let go of OCD just yet or face their fears. That means I spend a lot of time in what Motivational Interviewing calls “building readiness for change.” Although I use Motivational Interviewing sometimes for this stage, I more often use Acceptance and Commitment therapy (ACT) and Internal Family Systems (IFS). I also find these to be very helpful models when supporting with complex trauma.

When I learned ACT some time ago, it was all I could think about and do. An active, trandiagnostic, non-pathologizing model? Yes, please! I used it with everyone even though it didn’t necessarily fit everyone’s style. I was enthusiastic and wanted to practice. Then when I learned IFS, I did the same thing. Beginner me is very eager to try things out. Now I have a better sense of when to use each of these models, and when to use both of them, and am writing this post to pass on what I’ve learned.

What ACT and IFS Have in Common

While they come from different theoretical backgrounds, ACT and IFS actually share some important core values:

• Non-pathologizing orientation: Both approaches take an accepting stance toward suffering and symptoms. Instead of asking “what’s wrong with me?” they ask, “what is this part trying to protect me from?” (IFS) or “what is this emotion trying to move me toward?” (ACT).

• Transdiagnostic: Although ACT writing tends to have much to say on Anxiety, Depression, and PTSD, and IFS has much to say about Trauma, especially Complex Trauma, shame, and addictions, these models are both fully trans-diagnostic. That means that they are looking at processes rather than clusters of symptoms. They zoom out on suffering and its essential components, and both hold an understanding that often the solution is the problem - in other words, when we try to shield ourselves from experience, we reduce immediate distress at the expense of deeper knowing and connection.

• Emphasis on compassion and inner wisdom: Both models see humans as having within them what they need to succeed, and the therapy process is one of removing process barriers and reconnecting to wisdom, becoming more flexible, rather than changing.

• Mindfulness and presence: ACT teaches defusion and present-moment awareness; IFS focuses on Self-energy and witnessing parts. In both, there's a practice of stepping back from automatic reactivity and getting curious.

These models have so much in common that my chapter of ACT had a special event introducing IFS to practitioners who are already fluent in ACT, and many of us walked away thinking - these are some different tools and new language but essentially the same theory of healing. But they felt different in some key ways.

What’s different between these models?

I’ve learned through some mistakes not to blend these models at the risk of confusing clients, and that they are not received equally accross the board. One of the ways I differentiate these models is to think of them on a spectrum between analytical/conceptual and relational/experiential.

• ACT tends to be more structured and concrete.
  It’s built on six core processes (like cognitive defusion, values, committed action) and has a roadmap that can be easily taught and understood. This can make ACT especially helpful for clients who:

  • Appreciate clarity and logical scaffolding

  • Struggle with emotional overwhelm or ambiguity

  • Benefit from skills-focused interventions
    For people with OCD or ADHD, this can mean learning clear tools to relate differently to intrusive thoughts or rigid patterns.

• IFS is more fluid and relational.
  IFS guides clients in building an internal relationship with their “parts,” using curiosity and compassion to unburden protective roles and reconnect with exiled emotions. This works especially well for clients who:

  • Are drawn to experiential exploration

  • Want to develop internal trust and self-compassion

  • Find healing through visualization, emotion, and imagination
    For neurodivergent clients who’ve internalized shame or masking behaviors, IFS can be especially powerful in restoring a sense of wholeness and an inner relating that can get fragmented.

  • IFS sessions tend to be more client led and spontaneous - for clients who already have a lot of skills, this may be a more transformative process in some ways.

• For clients with OCD and/or autism—especially those who lean heavily on mental reviewing, rationalization, or internal problem-solving—IFS can sometimes feel too ambiguous or abstract at first. These clients often say things like:

“How do I know if it’s really a part, or just another intrusive thought?”
“What if I’m doing it wrong?”

In these cases, ACT’s concrete structure can be a safer entry point. Learning to “name the story,” make room for doubt, and take action based on values provides a grounded way to build tolerance for uncertainty and skills for the emotionanl experience that comes with exposure and response prevention.

I’m excited to bring both of these models to my toolkit to help build readiness for change, and help people build more connection and self-led, values based living. I hope this helps a little with the decision making process when both options are available.