State of the ACT Evidence

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This page will be updated approximately once every six months. Date of late update: August 2016. If you are aware of missing data, please contact the ACBS staff: "" <>

ACT is committed to a high standard of empirical evaluation. This includes not just controlled assessment and evaluations of outcomes but also the specification and evaluation moderations and of the putative processes of change. Furthermore, we also seek to understand the links between these processes of change and basic functional behavioral principles, including those drawn from RFT.

One web page is unable to collect together the growing evidence for all of the above areas at one time point or to keep it up to date going forward. More modestly, the three sections below aim to provide information on:

1. Organizations that describe ACT, or areas of ACT, as evidence based
2. Links to peer reviewed assessments of the ACT evidence base
3. Snapshots of the ACT RCT evidence base (a list of actual randomized controlled trials can be found at another page:; a list of mediational studies can be found at

1. Organizations that describe ACT, or areas of ACT, as evidence based:

A number of different organizations, external to ACBS, have stated that ACT is empirically supported in certain areas or as a whole according to their standards. These include:

i. American Psychological Association, Society of Clinical Psychology (Div. 12), Research Supported Psychological Treatments:

Chronic Pain - Strong Research Support
Depression - Modest Research Support
Mixed anxiety - Modest Research Support
Obsessive-Compulsive Disorder - Modest Research Support
Psychosis - Modest Research Support
For more information on what the "modest" and "strong" labels mean, click here

ii. SAMHSA's National Registry of Evidence-based Programs and Practices, ACT, last review July 2010.

2. Links to peer reviewed assessments of the ACT evidence base:

Below is a list of meta-analyses, systematic or narrative reviews of the ACT evidence base, either overall or in specific areas. They are presented in reverse chronological order, by year of publication.  

Atkins, P. W. B., Ciarrochi, J., Gaudiano, B. A., Bricker, J. B., Donald, J., Rovner, G., Smout, M., Livheim, F., Lundgren, T., Hayes, S. C. (in press). Departing from the essential features of a high quality systematic review of psychotherapy: A Response to Öst (2014) and recommendations for improvement. Behaviour Research and Therapy. doi: 10.1016/j.brat.2017.05.016. Strictly speaking this is not a meta-analysis, but it is a review of one farther down this list.

Gilpin, H. R., Keyes, A., Stahl, D. R., Greig, R. & McCracken, L. M. (2017). Predictors of Treatment Outcome in Contextual Cognitive and Behavioral Therapies for Chronic Pain: A Systematic Review. The Journal of Pain, 18, 1153-1164.

Hughes, L. S., Clark, J., Colclough, J. A., Dale, E., & McMillan, D. (2017). Acceptance and Commitment Therapy (ACT) for chronic pain: A systematic review and meta-analyses. Clinical Journal of Pain, 33, 552-568.
DOI: 10.1097/AJP.0000000000000425

Simpson , P. A., Mars, I., & Esteves, J. E. (in press). A systematic review of randomised controlled trials using Acceptance and Commitment Therapy as an intervention in the management of non-malignant, chronic pain in adults. International Journal of Osteopathic Medicine. doi:10.1016/j.ijosm.2017.03.001

Nicole N. Lønfeldt, Wendy K. Silverman, and Barbara H. Esbjørn (2017). A Systematic Review and Meta-analysis of the Association Between Third-Wave Cognitive Constructs and Youth Anxiety. International Journal of Cognitive Therapy, 10, 115-137. doi:10.1521/ijct.2017.10.2.115  (note that this is a review of ACT related concepts, not of ACT as an intervention)

Tonarelli, S. B., Pasillas, R., Alvarado, L., Dwivedi, A. & Cancellare, A. (2016). Acceptance and Commitment Therapy compared to treatment as usual in psychosis: A systematic review and meta-analysis. Journal of Psychiatry, 19, 366. doi:10.4172/2378-5756.1000366 

Hacker, T., Stone, P., & MacBeth, A. (2016). Acceptance and commitment therapy - Do we know enough? Cumulative and sequential meta-analyses of randomized controlled trials. Journal of Affective Disorders, 190, 551-565. DOI: 10.1016/j.jad.2015.10.053

Graham, C. D., Gouick, J., Krahe, C., et al (2016). A systematic review of the use of Acceptance and Commitment Therapy (ACT) in chronic disease and long-term conditions. Clinical Psychology Review, 46, 46-58.

Brown, M., Glendenning, A., Hoon, A. E. & John, A. (2016). Effectiveness of web-delivered acceptance and commitment therapy in relation to mental health and well-being: A systematic review and meta-analysis. Journal of Medical Internet Research, 18, e221. DOI: 10.2196/jmir.6200

Veehof, M. M., Trompetter, H. R., Bohlmeijer, E. T. & Schreurs, K. M. G. (2016) Acceptance- and mindfulness-based interventions for the treatment of chronic pain: A meta-analytic review. Cognitive Behaviour Therapy, 45, 5-31. DOI: 10.1080/16506073.2015.1098724

Ducasse, D., & Fond, G. (2015). Acceptance and commitment therapy. Encephale-Revue De Psychiatrie Clinique Biologique Et Therapeutique, 41, 1-9. DOI: 10.1016/j.encep.2013.04.017

Lee, E. B., An, W., Levin, M. E., & Twohig, M. P. (2015). An initial meta-analysis of Acceptance and Commitment Therapy for treating substance use disorders. Drug and Alcohol Dependence, 155, 1-7. DOI: 10.1016/j.drugalcdep.2015.08.004

Godfrey, K. M., Gallo, L. C., & Afari, N. (2015). Mindfulness-based interventions for binge eating: a systematic review and meta-analysis. Journal of Behavioral Medicine, 38, 348-362. DOI: 10.1007/s10865-014-9610-5

A-Tjak, J. G., Davis, M. L., Morina, N., Powers, M. B., Smits, J. A., & Emmelkamp P. M., (2015) A meta-analysis of the efficacy of acceptance and commitment therapy for clinically relevant mental and physical health problems.  Psychotherapy and Psychosomatics, 84(30), 30-36.
DOI: 10.1159/000365764
Full Text: Available at DOI 

Cavanagh, K., Strauss, C., Forder, L., & Jones, F. (2014). Can mindfulness and acceptance be learnt by self-help?: A systematic review and meta-analysis of mindfulness and acceptance-based self-help interventions. Clinical Psychology Review, 34, 118-129. DOI: 10.1016/j.cpr.2014.01.001 

Ost, L. G. (2014). The efficacy of Acceptance and Commitment Therapy: an updated systematic review and meta-analysis. Behaviour Research and Therapy, 61, 105-121.
DOI: 10.1016/j.brat.2014.07.018
Full Text: Available at DOI

Swain, J., Hancock, K., Hainsworth, C., & Bowman, J. (2013). Acceptance and commitment therapy in the treatment of anxiety: a systematic review. Clin Psychol Rev, 33(8), 965-978. doi:10.1016/j.cpr.2013.07.002
Full Text: Available at DOI

Klainin-Yobas, P., Cho, M. A. A., & Creedy, D. (2012). Efficacy of mindfulness-based interventions on depressive symptoms among people with mental disorders: A meta-analysis. International Journal of Nursing Studies, 49, 109-121. DOI: 10.1016/j.ijnurstu.2011.08.014

Smout, M.F., Hayes, L., Atkins, P.W.B., Klausen, J., & Duguid, J.E. (2012). The empirically supported status of acceptance and commitment therapy: An update. Clinical Psychologist, 16, 97-109.
DOI: 10.1111/j.1742-9552.2012.00051.x
Full Text: ACBS Website

Veehof, M. M., Oskam, M-J., Schreurs, K. M. G., & Bohlmeijer, E. T. (2011). Acceptance-based interventions for the treatment of chronic pain: A systematic review and meta-analysis. Pain, 152, 533–542.
DOI: 10.1016/j.pain.2010.11.002

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, 125-162.
Full Text: ACBS Website

Powers, M.B., Vörding, M. & Emmelkamp, P.M.G. (2009). Acceptance and commitment therapy: A meta-analytic review. Psychotherapy and Psychosomatics, 8, 73-80.
DOI: 10.1159/000190790
Full Text: ACBS Website

Gaudiano, B. A. (2009). Öst's (2008) Methodological Comparison of Clinical Trials of Acceptance and Commitment Therapy versus Cognitive Behavior Therapy: Matching Apples with Oranges? Behaviour Research and Therapy, 47, 1066-1070.
DOI: 10.1016/j.brat.2009.07.020
Full Text: ACBS Website

Öst, L. (2008). Efficacy of the third wave of behavioral therapies: A systematic review and meta-analysis. Behaviour Research and Therapy, 46(3), 296-321.
DOI: 10.1016/j.brat.2007.12.005
Full Text: ACBS Website

Hayes, S. C., Luoma, J., Bond, F., Masuda, A., & Lillis, J. (2006). Acceptance and Commitment Therapy: Model, processes, and outcomes. Behaviour Research and Therapy, 44(1), 1-25.
DOI: 10.1016/j.brat.2005.06.006
Full Text: ACBS Website


3. Mediational analyses

ACT is a process-oriented approach and the list of studies testing mediation or moderation is quite large. As of Spring 2016 we were aware of approximately 45 mediational studies. This list is rapidly growing. A daughter page has a partial list.


4. Qualitative Research

After the first three RCTs in the early 1980's ACT research turned toward transcript analysis and qualitative research. Examples are the first ACT dissertations done at the Univeristy of Nevada by Sue McCurry and Durriyah Khorakiwala. This work in turn lead to the first item set for the AAQ, and to the commonly used ACT adherence measures, in addition to the protocol described in the first ACT book in 1999.

Qualitative work is hard to do but it has continued throughout the ACT research program. Examples are presents in a daughter page. If you find any more send them to ACBS staff to add to the list.


5. Snapshots of the ACT RCT evidence base:

As of December 2016, there are 171 randomized controlled trials (RCTs) of ACT published. Details of each of these studies, along with links to the original research articles, can be found here (a daughter page to this page) Below, we provide a snapshot of this ACT RCT evidence-base, summarizing clinical areas in order of the number of published RCTs. This list is current as of August 2016. It is, of course, acknowledged that evidence from RCTs is only one part of evidence-based practice, and for some questions and issues it is arguably not the most important.


Area: Number of studies: RCT page study number(s):
Pain 19 9, 14, 20, 24, 31, 37, 39, 52, 55, 65, 68, 73, 74, 75, 91, 106, 122, 126, 127
Depression 16 1, 2, 26, 41, 43, 47, 49, 66, 67, 69, 78, 89, 92, 114, 125, 133
Stress 13 3, 34, 35, 46, 61, 62, 63, 64, 79, 83, 85, 118, 119
Anxiety 14 5,19, 22, 45, 48, 59, 86, 94, 108, 110, 112, 130, 131, 136
Various 10 17, 32, 33, 40, 51, 97, 105, 107, 111, 117
Weight Loss 7 25, 27, 44, 70, 72, 87, 116
Substance Abuse 9 6, 29, 53, 58, 84, 103, 121, 123, 134
Smoking 5 8, 42, 71, 98, 99
Cancer 5 15, 57, 81, 90, 101
Eating Disorders 4 30, 56, 60, 76
Social Anxiety 4 77, 80, 82, 96
Psychosis 3 4, 13, 36
Epilepsy 2 11, 23
Borderline Personality Disorder 2 12, 54
Diabetes 2 18, 93
Tinnitus 2 38, 50
Parenting 3 95, 100, 124
Stigma 4 7, 16, 104, 128
Trichotillomania 1 10
OCD 1 28
Prevention 1 88
Exercise 3 113, 115, 129
Quality of Life 2 102, 132
Aggression 1 109
Procrastination 1 120
Pornography 1 135
Training 1 21