Depression, Bipolar & Grief Counselling Blog

Acceptance and Commitment Therapy (ACT) – a review

A review of ACT (Acceptance and Commitment Therapy) by Lee Hopkins
Near Lady Bay, Fleurieu Peninsula, South Australia


Acceptance and Commitment Therapy: the foundations

This post will look at Acceptance and Commitment Therapy (ACT) and its foundations of Functional Contextualism (FC), Applied Behavioural Analysis (ABA) and Relational Frame Theory (RFT). It will consider the latest research and meta-analyses of the efficacy of ACT and will conclude that whilst ACT shows promise as a therapeutic tool for many psychological conditions, it shows no greater promise than traditional Cognitive Behavioural therapies (CBT).


ACT as we currently understand it has been a long time coming (Harris, 2009). Seeing that as far back as 1986 randomised controlled trials (RCT) were showing its efficacy in treating depression, the journey from a ‘possibly useful’ new therapeutic option to a now widely-recognised and talked-about therapy has been a long, slow but behind-the-scenes busy one.

Steven Hayes, the originator and champion of ACT, explains (Harris, 2008; cited in Harris, 2009) that the time between initial development and its current popularity has been time well spent on establishing sound theoretical, measurement and philosophical bases. Without such underpinnings, explains Hayes, ACT could have withered under intense scrutiny and died.

Functional Contextualism (FC)

Functional Contextualism is the underlying philosophy of the ‘third wave’ of behavioural therapies, of which ACT is one (Benson, Sevier, & Christensen, 2014). From the perspective of FC, no thought we might have is considered problematic, dysfunctional or pathological (Harris, 2009); it is only the context within which the thought operates that determines its meaning, and that meaning is experiential (Jonassen, 2006). Thoughts can be toxic and harmful, but depending on whether we are cognitively fused with them or in a state of mindful diffusion those same thoughts can either hold us back or not from valued living. FC seeks to understand people within their environments, and that whilst behaviour can look very similar in different circumstances, the function of that behaviour can be very different (Boone, Mundy, Morrissey Stahl, & Genrich, 2015).

FC views ‘truth’ as contextual and pragmatic (Hayes, Luoma, Bond, Masuda, & Lillis, 2006). Given a set of circumstances and thoughts to work with, FC chooses to work with ‘what works for a given goal’ (Boone et al., 2015). Therefore, a FC therapist would not ask a client to examine the veracity of their thought, as a CBT practitioner would, but instead ask whether it is useful in the pursuit of a particular client-held value or goal. As Boone and his colleagues note, a pragmatic-focused criterion keeps therapists from getting bogged down in ‘what is reality’ questions and instead sharpens their focus onto what effectively helps people.

It should be noted that FC is not a widely-published academic theory; four authors (Steven Hayes, Jennifer Gregg, Elizabeth Gifford and Anthony Biglan) account for the majority of the literature on FC. As Jonassen (2006, p. 45) points out, “It is an interesting theory worthy of consideration, but it is not a major neo-behaviorist movement.”

Relational Frame Theory (RFT)

FC starts with basic principles of learning theory such as operant conditioning (e.g. positive and negative reinforcement) and classical conditioning; Relational Frame Theory takes FC further by seeking to account for the complexity of human behaviour through taking into account the role of language in learning. A substantial literature demonstrates the potential for RFT to contribute to the understanding of language and cognitive development (Cullinan & Vitale, 2009). RFT is a behaviour analytic approach to the study of human language and cognition.

RFT describes a process whereby humans learn to relate to stimuli in their social environment based on assumptions and conventions that are social and cultural. ACT is an intervention, grounded in RFT, that addresses problem behaviours that arise from human relations derived from language and cognition (McKeel & Dixon, 2014). ACT notes that individuals engage in experiential avoidance which leads them to undesirable behaviours. What is noted in RFT is that humans don’t take into account just the physical characteristics of given stimuli, but that they attach all manner of interpretations to it, ‘framing’ the stimuli. Relational framing is thought to be an unconscious process, but one that is capable of being consciously considered (McLaren, Dillard, Tusing, & Solomon, 2014). RFT states that people interpret or ‘frame’ messages and thoughts as relevant to either of two domains: dominance-submissiveness (reflecting the power, influence or status between communicators) or affiliation-disaffiliation, which encompasses the degree of solidarity, liking or esteem that a communication receiver has for another communicator (Dillard et al., 1996; cited in McLaren et al., 2014). Framing is an unconscious process precisely because it needs to be fast-moving; people must quickly figure out how to appropriately respond to a message during an interaction. According to RFT, the various relational frames that people construct are said to possess three properties: mutual entailment, combinatorial entailment and transformation of function. It is beyond the scope and length of this essay to do more than note the existence of these three properties. Each is complex in design and description.

To many the theory remains controversial and complex (Dymond, May, Munnelly, & Hoon, 2010). To others the fact that the vast majority of academic publications about RFT occur in low-impact or no-impact journals suggests low levels of academic support except amongst a small group of practitioners—somewhat akin to the existence of journals that take into account religious perspectives (e.g. Journal of Psychology & Christianity, Journal of Psychology & Theology), it is possibly a case of the converted speaking only to the converted. There doesn’t appear to have been a concerted wider effort at evangelism. Also of note is that the studies, whilst numerous, have most often times been conducted in an experimental setting and with very small numbers of subjects. It would be nice to see RFT studies conducted in broader settings.

Applied Behavioural Analysis (ABA)

Applied behaviour analysts have been helping people to enhance the quality of their lives for decades (see, for example, Zifferblatt & Hendricks, 1974). ABA is a scientific approach to the study of behaviour, paying close attention to the social validity of concerns and outcomes. As Gambrill (2013) notes, thousands of studies can attest that people’s lives can be improved by drawing on basic behavioural principles. It is in the applicability of theory that ABA shines, particularly in educational settings, where it has been shown to be extremely helpful with autism (Lovitt, 2012; see also

ABA allows for the prediction and influence of behaviour. Whilst a multi-faceted tool (see Lovitt, 2012 for a breakdown of the seven components: direct measurement, contingency management, precise behavioural language, behavioural processes, self-management, pinpointing behaviours, and charting), of particular interest to ACT is functional behavioural analysis, which asks the question, “What purpose does this behaviour serve?” ABA has a simple A-B-C formula to help with answering that question; Antecedent-Behaviour-Consequence. ‘Antecedent’ asks what happens before a behaviour that plays a major role in influencing it. ‘Behaviour’ is the behaviour we have under consideration, the focus of our investigation (perhaps because the client feels that it is ‘wrong’ behaviour). ‘Consequence’ is a look at the effects the behaviour has on the self, others or the environment. By analysing the ‘ABC’ of a problem behaviour we free up the client to be able to explore and clarify their values. From this value awareness, the client is able to make different choices about what to do when troubling thoughts occur, behaviour that has more life-enhancing outcomes.

Acceptance and Commitment Therapy (ACT)

There is not the space here to show in any great depth what ACT is, other than to note that more than 60 books on ACT have been written, so further elucidation is not far from hand (Hayes, Strosahl, & Wilson, 2012). In addition, hundreds of academic papers have been written about the therapy, suggesting that ACT can be efficacious—either on its own or when used in conjunction with other therapies—when treating depression, OCD, workplace stress, chronic pain, the stress of terminal cancer, anxiety, PTSD, anorexia, heroin abuse, marijuana abuse, and even schizophrenia (Harris, 2006). It has also shown promise as an internet-based tool (Lappalainen et al., 2014).

ACT is a ‘third wave’ therapy; it is characterised by an openness to older clinical traditions, it has a focus on contextual change, an emphasis on function over form, and an interest in the construction of flexible and effective repertoires (Hayes, 2004).

ACT relies on the philosophy of FC to provide its pragmatic base. FC, it should be remembered, considers what is ‘true’ to be what is ‘working’. In ACT, holds Hayes (2004), there is a conscious posture of acceptance and openness to all psychological events, even if they are seen as ‘negative’, ‘irrational’, or even ‘psychotic’.

RFT in ACT points directly to the likelihood of cognitive fusion and experiential avoidance. In ACT it is the tendency to take experiences literally and to fight against them that is viewed as harmful. With ABA, ACT therapists are able to measure what the antecedents and consequences of behaviour are.

The principle aim of ACT is to dismantle inflexible repertoires, favouring the acceptance of a feared private event when that private event generates counterproductive attempts to avoid or control (Ruiz, 2010). In order to meet its objectives, ACT makes use of paradoxes, metaphors and experiential exercises, training the client to be present with their feared private event and to choose to behave in a way that aligns with their stated values.

ACT assumes that within language and learning processes lie the origins of despair and pain (Jones & Butman, 2011). In this regard Hayes has himself drawn a line to both biblical (Hayes, Strosahl, & Wilson, 1999) and to Buddhist (Hayes, 2002) views of suffering and its amelioration.


Several meta-analyses have been conducted on ACT. Öst (2008, 2014) found little evidence for the alleged greater efficacy of ACT compared to traditional treatments. Ruiz (2012) conducted a comparison review of ACT and CBT and found a positive result for ACT, whilst acknowledging the small sample sizes of most of the studies. Powers et al. (2009) found “there is no evidence yet that ACT is more effective than established treatments.” But Levin and Hayes (2009) re-analysed Powers et al.’s database and found that ACT was better than established treatments. Powers and Emmelkamp respectfully disagreed and stuck by their original finding (Powers & Emmelkamp, 2009).

Hayes and his colleagues noted with dismay that ACT was continually being compared with CBT and wrote a plea to colleagues to stop that and instead measure ACT on its own terms (Hayes, Levin, Plumb-Vilardaga, Villatte, & Pistorello, 2013), perhaps feeling that ACT had been around long enough to warrant a more serious level of attention and acknowledgement.

It should be noted that not all meta-analysts agree with each other. Morina, A-Tjak and Emmelkamp (2015) took issue with a peer who commented that their meta-analysis (A-Tjak et al., 2015) and that of Öst (2014) reached “strikingly contrasting conclusions” (A-Tjak et al. found that ACT can provide similar outcomes as established psychological interventions; Öst found no such finding for any disorder). Morina and his colleagues argued that issues of trial relevancy and inclusion, the statistical procedures used to analyse the data, and the criteria applied to interpret the results all play a part in the different findings of the two meta-analyses. What is clear is that small sample sizes can hinder interpretations. As Morina et al. point out, there needs to be a standardised procedure for meta-analyses so that apples can be compared with apples (and also so that potential bias can be reduced or eliminated).


ACT is a relatively new weapon in the counsellor’s armoury. It works by helping the client psychologically ‘unhook’ from problematic thoughts and instead help the client consider and decide whether the thoughts work in the client’s best interests and towards the client’s values. By basing itself on proven theories and philosophies it sits within the ‘third wave’ of behavioural therapies—therapies that build on solid empirical foundations of ‘first’ and ‘second wave’ behaviourism and use mindfulness to facilitate cognitive defusion. Several meta-analyses of ACT have been conducted, most often comparing ACT to traditional, ‘first wave’, CBT, and the results have been mixed and controversial.


A-Tjak, J. G. L., Davis, M. L., Morina, N., Powers, M. B., Smits, J. A. J., & Emmelkamp, P. M. G. (2015). A meta-analysis of the efficacy of Acceptance and Commitment Therapy for clinically relevant mental and physical health problems. Psychotherapy and Psychosomatics, 84(1), 30-36.

Benson, L. A., Sevier, M., & Christensen, A. (2014). Reply to the commentaries: Of course, we do not yet know what it is all about, but Functional Contextualism is a good place to start. Journal of Marital and Family Therapy, 40(1), 1-4. doi: 10.1111/jmft.12036

Boone, M. S., Mundy, B., Morrissey Stahl, K., & Genrich, B. E. (2015). Acceptance and Commitment Therapy, Functional Contextualism, and Clinical Social Work. Journal of Human Behavior in the Social Environment, 25(6), 643-656. doi: 10.1080/10911359.2015.1011255

Cullinan, V., & Vitale, A. (2009). The contribution of Relational Frame Theory to the development of interventions for impairments of language and cognition. The Journal of Speech and Language Pathology – Applied Behavior Analysis, 4(1), 132-145.

Dymond, S., May, R. J., Munnelly, A., & Hoon, A. E. (2010). Evaluating the evidence base for Relational Frame Theory: A citation analysis. The Behavior Analyst, 33(1), 97-117.

Gambrill, E. (2013). Birds of a Feather: Applied Behavior Analysis and Quality of Life. Research on Social Work Practice, 23(2), 121-140. doi: 10.1177/1049731512465775

Harris, R. (2006). Embracing your demons: An overview of Acceptance and Commitment Therapy. Retrieved 12th August, 2015, from

Harris, R. (2008). An interview with Steven Hayes. The Happiness Trap Newsletter, (November).

Harris, R. (2009). ACT made simple: An easy-to-read primer on Acceptance and Commitment Therapy. Oakland, CA, USA: New Harbinger.

Hayes, S. C. (2002). Buddhism and acceptance and commitment therapy. Cognitive and Behavioral Practice, 9(1), 58-66. doi:

Hayes, S. C. (2004). Acceptance and commitment therapy, relational frame theory, and the third wave of behavioral and cognitive therapies. Behavior Therapy, 35(4), 639-665. doi:

Hayes, S. C., Levin, M. E., Plumb-Vilardaga, J., Villatte, J. L., & Pistorello, J. (2013). Acceptance and Commitment Therapy and Contextual Behavioral Science: Examining the progress of a distinctive model of behavioral and cognitive therapy. Behavior Therapy, 44(2), 180-198. doi:

Hayes, S. C., Luoma, J. B., Bond, F. W., Masuda, A., & Lillis, J. (2006). Acceptance and Commitment Therapy: Model, processes and outcomes. Behaviour Research and Therapy, 44(1), 1-25. doi:

Hayes, S. C., Strosahl, K. D., & Wilson, K. G. (1999). Acceptance and Commitment Therapy: An experiential approach to behavior change. New York: Springer.

Hayes, S. C., Strosahl, K. D., & Wilson, K. G. (2012). Acceptance and Commitment Therapy: The process and practice of mindful change (2nd ed.). New York: Guilford.

Jonassen, D. H. (2006). A Constructivist’s perspective on Functional Contextualism. Educational Technology Research and Development, 54(1), 43-47. doi: 10.1007/s11423-006-6493-3

Jones, S. L., & Butman, R. E. (2011). Modern psychotherapies: A comprehensive Christian appraisal (2nd Edition). Westmont, IL, USA: InterVarsity Press.

Lappalainen, P., Granlund, A., Siltanen, S., Ahonen, S., Vitikainen, M., Tolvanen, A., & Lappalainen, R. (2014). ACT Internet-based vs face-to-face? A randomized controlled trial of two ways to deliver Acceptance and Commitment Therapy for depressive symptoms: An 18-month follow-up. Behaviour Research and Therapy, 61, 43-54. doi:

Levin, M. E., & Hayes, S. C. (2009). Is Acceptance and Commitment Therapy superior to established treatment comparisons? Psychotherapy and Psychosomatics, 78(6), 380.

Lovitt, T. C. (2012). Applied Behavior Analysis: A Method That Languished but Should Be Restored. Intervention in School and Clinic, 47(4), 252-256. doi: 10.1177/1053451211424598

McKeel, A., & Dixon, M. (2014). Furthering a behavior analytic account of self-control using relational frame theory. Behavioral Development Bulletin, 19(2), 111-118.

McLaren, R. M., Dillard, J. P., Tusing, K. J., & Solomon, D. H. (2014). Relational Framing Theory: Utterance form and relational context as antecedents of frame salience. Communication Quarterly, 62(5), 518-535.

Morina, N., A-Tjak, J. G. L., & Emmelkamp, P. M. G. (2015). Reducing biases in meta-analyses: Reply to Hertenstein and Nissen. Psychotherapy and Psychosomatics, 84(4), 252.

Öst, L.-G. (2008). Efficacy of the third wave of behavioral therapies: A systematic review and meta-analysis. Behaviour Research and Therapy, 46(3), 296-321.

Öst, L.-G. (2014). The efficacy of Acceptance and Commitment Therapy: An updated systematic review and meta-analysis. Behaviour Research and Therapy(61), 105.

Powers, M. B., & Emmelkamp, P. M. G. (2009). Response to ‘Is Acceptance and Commitment Therapy Superior to Established Treatment Comparisons?’. Psychotherapy and Psychosomatics, 78(6), 380a-381.

Powers, M. B., Zum Voerde Sive Voerding, M. B., & Emmelkamp, P. M. G. (2009). Acceptance and Commitment Therapy: A Meta-Analytic Review. Psychotherapy and Psychosomatics, 78(2), 73-80. doi:

Ruiz, F. J. (2010). A Review of Acceptance and Commitment Therapy (ACT) Empirical Evidence: Correlational, Experimental Psychopathology, Component and Outcome Studies. International Journal of Psychology and Psychological Therapy, 10(1), 125-162.

Ruiz, F. J. (2012). Acceptance and Commitment Therapy versus Traditional Cognitive Behavioral Therapy: A Systematic Review and Meta-analysis of Current Empirical Evidence. International Journal of Psychology and Psychological Therapy, 12(3), 333-357.

Zifferblatt, S. M., & Hendricks, C. G. (1974). Applied behavioral analysis of societal problems: Population change, a case in point. American Psychologist, 29(10), 750-761.


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