The 6 Processes of 'Acceptance and Commitment Therapy' That Lighten the Heart

Hello, this is Kito. Today, I would like to introduce a research paper. Recently, I introduced the concept of “psychological flexibility.” Today, I am introducing another paper related to that. The theme is “ACT.”

Now, “ACT (Acceptance and Commitment Therapy)” is an approach to increasing psychological flexibility. It seems to be known to those in the know as a powerful method, often referred to as “third-wave psychotherapy” (though I wasn’t aware of it... oops).

In this context, this paper presents a meta-analysis of ACT including data from over 5,000 people, demonstrating the effectiveness of its processes. I found it to be a persuasive and practical paper. So, let’s take a look right away! Here we go.

This paper

Key points of the paper in 30 seconds

• ACT is an approach that increases psychological flexibility not by changing the “content of thoughts,” but by changing the “way of relating (context)” to thoughts.

• It is based on a unique theory (Relational Frame Theory: RFT) that avoids the “paradoxical worsening” caused by direct control of thoughts, which traditional “Cognitive Behavioral Therapy (CBT)” struggled with.

• A meta-analysis including data from over 5,000 people showed that ACT processes (acceptance and flexibility) are strongly associated with mental health and work performance.

• Its effectiveness has been proven in a surprisingly wide range of fields, including not only mental illness but also workplace stress management, diabetes self-management, smoking cessation, and chronic pain.

• It was found that the six core processes (acceptance, defusion, present moment, self-as-context, values, and commitment) interact to improve the quality of life.

The 6 core processes of ACT

Psychological flexibility refers to “the ability to flexibly adapt thoughts and behaviors according to the situation,” and it is said that there are “six processes” in ACT to increase this. Specifically, they are as follows.

These are summarized as two approaches: “Mindfulness and acceptance processes (1–4)” and “Commitment and behavior change processes (5–6).”
The difference from the well-known mindfulness is specifically the inclusion of the “commitment and behavior change processes.”

Background and purpose of the study

Previous behavioral therapies have evolved from the “first generation” based on learning theory to the “second generation (CBT)” which emphasizes the modification of thoughts.
However, recent studies have pointed out a contradiction: “The more you try to erase negative thoughts, the more you are dominated by those thoughts.”

The purpose of this study is to present the theoretical model of ACT, a representative of the “third wave” that solves this difficult problem, and to comprehensively examine the evidence from existing correlational studies, process-of-change studies, and outcome comparison studies.

Research methods

This paper provides a comprehensive review of almost all existing literature up to the spring of 2005 that directly examined ACT and its components.

• Design: Meta-analysis of correlational studies, component analysis (micro-studies), and reviews of randomized controlled trials (RCTs) along with mediation analysis.

• Participants: 27 correlational studies including a total of 5,616 participants, as well as numerous clinical and non-clinical samples.

• Measures Used:

  • Acceptance and Action Questionnaire (AAQ): Measures psychological flexibility and experiential avoidance.

  • Automatic Thoughts Questionnaire (ATQ-B): Measures the believability of thoughts (defusion).

  • Others include a wide range of measures such as the BDI (depression), GHQ (general health), and HbA1c (blood glucose levels).

• Analytical Methods: Calculation of weighted average effect sizes via meta-analysis, and mediation analysis based on procedures such as MacKinnon (2003).

Key Findings (What We Learned)

Finding 1: Psychological flexibility has a moderate to strong correlation with broad quality of life.

Integrating 27 studies, a significant correlation with a weighted effect size of 0.42 was found between psychological flexibility measures (AAQ) and outcomes such as psychopathology, stress, pain management, and job performance. This indicates that the more flexible the mind, the better both health and work outcomes tend to be.

Finding 2: ACT works through a 'process' different from traditional therapies.

Mediation analysis revealed that improvement through ACT occurs not by reducing the 'frequency of thoughts,' but by lowering their 'believability' (the degree to which one takes them as absolute truth). Conversely, this process was not observed in traditional CBT, suggesting it is likely a mechanism unique to ACT.

Finding 3: It demonstrates high effectiveness for serious problems and in follow-up surveys.

When compared to active structured interventions, the effect size of ACT tended to be larger at follow-up (d=1.41) than immediately after treatment (d=0.58). This suggests that the skills learned in ACT are integrated into life over time, leading to long-term change.

Summary and Thoughts

I can certainly relate to the feeling that the more you think, 'I must get rid of this anxiety' or 'I must deal with these negative emotions,' the bigger the monster in your mind becomes!

In that context, I felt that the flow of 'Acceptance → Defusion → Mindfulness → Observing Self' to separate oneself from emotions, and then connecting to action by committing to values one wants to cherish, is very practical.

I also sometimes start a pessimistic 'one-person theater' in my head after giving a training seminar, thinking, 'That might not have been great...' but I feel like I could become more level-headed just by thinking, 'That is not necessarily a fact; it is just me thinking that' (defusion, observing self).

The fact that its effectiveness has been verified by studies involving 5,600 people is also persuasive, and it has made me want to explore it further and learn how to master it.

Thank you for reading until the end!