Definition
Acceptance and Commitment Therapy (ACT, pronounced as the word "act") was developed by Steven C. Hayes and colleagues from Relational Frame Theory (RFT), a functional theory of language and cognition. ACT does not attempt to directly reduce symptoms — it seeks to change the relationship the client has with their thoughts, emotions, and sensations, increasing what Hayes calls "psychological flexibility."
How it's used
ACT works through six core therapeutic processes, grouped into two categories:
Openness — what the client learns to do with difficult experiences:
- Cognitive defusion: observing thoughts as mental events, not literal truths.
- Acceptance: allowing difficult emotions to be present without fighting them.
Presence — the foundation from which one operates:
- Contact with the present moment: mindful attention to the here and now.
- Self-as-context: stable identity that observes without fusing with mental contents.
Commitment — the direction of change:
- Values: clarifying what truly matters to the client.
- Committed action: value-guided behavior, even in the presence of discomfort.
When to apply
ACT has evidence for depression, anxiety, chronic pain, addictions, work-related stress, and conditions where more directive approaches have generated resistance. It is especially useful when the client has "tried everything" and the attempt to control symptoms has become the problem.
Historical origin
Steven Hayes, professor at the University of Nevada, began developing ACT in the 1980s from radical behavioral psychology. The first edition of Acceptance and Commitment Therapy (Hayes, Strosahl and Wilson) was published in 1999 and is considered the foundational text. ACT is part of the "third wave" of behavioral therapies, alongside DBT, MBCT, and behavioral activation therapy.
How CauceOS supports it
CauceOS includes an ACT note template that records the processes worked in session, the defusion or acceptance exercises used, and the values clarification performed. Alerts can be configured to detect intense cognitive fusion language or marked experiential avoidance.
Related terms
- CBT — first and second wave; ACT emerges as an evolution
- DBT — third wave with emphasis on emotional regulation and dialectics
- MI — shares respect for autonomy and non-confrontation
References
- Hayes, S. C., Strosahl, K. D., & Wilson, K. G. (1999). Acceptance and Commitment Therapy. Guilford.
- Harris, R. (2009). ACT Made Simple. New Harbinger.
- Hayes, S. C. (2019). A Liberated Mind. Avery.