Acceptance and Commitment Therapy (ACT), pronounced as “act” rather than spelling out the letters, is a contemporary “third wave” behaviour therapy. It is an empirically grounded process approach built upon the foundations of traditional behaviour therapy and Cognitive Behavioural Therapy (CBT). ACT is an evidence-based intervention supported by decades of research, including over 300 randomized controlled trials. A key feature is that its underlying theory, Relational Frame Theory (RFT), was developed and extensively researched before the therapy itself was fully formed. It is also rooted in the philosophical principle of functional contextualism, which emphasizes examining behaviour within its context and considering its function.
The primary goal of ACT is to increase psychological flexibility. Psychological flexibility is defined as the ability to be open to one’s present experience, voluntarily shift attention to where it is needed, and develop habits aligned with one’s most cherished values. Rather than focusing primarily on symptom reduction or trying to make people “feel good,” ACT aims to help clients live a full, rich, and meaningful life, even in the presence of discomfort, distressing emotions, or challenging circumstances. It achieves this by changing a person’s relationship with their internal experiences (thoughts, feelings, sensations, memories) instead of trying to control, suppress, or eliminate them.
ACT works through six core, interdependent processes, often referred to as the Hexaflex:
- Acceptance: Being open and willing to experience one’s internal events (emotions, sensations, thoughts) exactly as they are, even if they are unwanted or uncomfortable. This is an active process of embracing experience, not passive resignation. It is presented as the opposite of experiential avoidance.
- Cognitive Defusion: Learning to take thoughts less literally, seeing them as just thoughts—mental events or language—rather than absolute truths or fused with reality. The aim is to loosen the hold thoughts have on behaviour by changing the relationship to them, not their content.
- Contacting the Present Moment: Developing awareness and paying attention to the here and now, including internal experiences and the external world, in a flexible, non-judgmental, and open way (mindfulness). This helps counter the tendency to get lost in verbal processes like worrying or rumination.
- Self-as-Context (Observing Self): Developing a perspective of oneself as the context or space in which thoughts, feelings, and sensations occur, rather than identifying solely with the content of those experiences. It provides a broader, transcendent sense of self.
- Values: Identifying and clarifying what is deeply important and meaningful in one’s life. Values serve as a compass, providing direction and purpose, which motivates engagement in difficult work and committed action.
- Committed Action: Taking and maintaining concrete steps and patterns of behaviour that are consistent with one’s chosen values, even when difficult internal experiences are present. This involves “doing” what matters, rather than waiting to “feel like” doing it.
ACT posits that psychological problems often arise from psychological inflexibility fostered by cognitive fusion (getting overly entangled with thoughts) and experiential avoidance (trying to control or escape difficult internal experiences). This avoidance is a core target in ACT because it often makes suffering worse and restricts life. ACT aims to undermine this struggle and the often unworkable agenda of control.
When applied to anxiety, ACT teaches clients to accept anxious thoughts, worries, bodily sensations, and the circumstances that occasion them, while directing their attention and efforts towards living a life guided by their values. Anxiety is not seen as an obstacle to be eliminated before life can begin, but as a part of the human experience that can accompany valued living. Techniques like exposure (referred to as FEEL exercises) are reframed within ACT not for symptom reduction, but to foster willingness to experience discomfort in the service of values and to expand one’s behavioural repertoire.
The therapist’s stance in ACT is characterized by compassion, genuineness, collaboration, and non-judgment. Therapists aim to model psychological flexibility, focusing on what “works” for the client in moving towards their values rather than arguing or convincing them of a particular viewpoint.
ACT is applicable across a wide range of psychological and behavioral issues, not limited to anxiety, and can be used in various settings, sometimes integrating other evidence-based techniques when they align with ACT’s principles.