State of the ACT Evidence

  • See the attachments at the bottom of the page for more recent lists of studies (if you see nothing it is because you are not logged in; do that first)

The ACT / RFT tradition is committed to a high standard of empirical evaluation, including not just controlled assessment and evaluations of outcomes but also specification and evaluation of the putative processes of change, and linkage of these processes to a basic program of research that seeks to explain them in terms of functional behavioral principles, including those drawn from RFT.

The efficacy and effectiveness data on ACT are positive, but preliminary. A July 2008 PowerPoint presentation of the evidence can be downloaded above. Also above is a table showing effect sizes for the ACT outcome literature. A meta-analysis, Hayes, Luoma, Bond, Masuda, & Lillis, 2006, was published in Behaviour Research and Therapy in January 2006 and is available in the publications list or by clicking on the emboldened link. There are more recent (and more critical) reviews from others such as Powers et al (2009) and Ost (2008), and responses to those criticisms.

As of March 2012 there are just under 60 RCTs of ACT published or in press. The studies average a bit over 75 participants each — which totals to over 4000 participants. Over half of this literature has appeared since 2009 so even the table below is already out of date. About 40% of the literature originated outside of the United States — it is truly and international research program.

ACT is now considered to an empirically supported treatment on the American Psychological Association Division 12 list of empirically-based treatments with moderate support in depression and strong support in pain (, and it is listed as an evidence-based practice on SAMHSA’s National Registry of Evidence-based Programs and Practices( It is approaching that level in areas such as smoking, psychosis, substance abuse, and some areas of anxiety.

We recommend ACT for problem areas where it is considered to be an evidence-based practice. That would include pain and depression; as of March 2012 it arguably it could include smoking, substance abuse, OCD, mixed anxiety disorders, psychosis, worksite stress, and a few others areas. We also recommend it on an experimental basis with any problem that fits the underlying model (e.g., the problem appears to involve cognitive fusion, or experiential avoidance, or a lack of clarity of values, and resulting inactivity, inflexibility, and ineffectiveness) provided it is used with systematic evaluation and there is a good reason not to use existing EBPs first (e.g., if they have already failed; client rejects their use). We think that approach is particularly appropriate for the problems in the following table, since at least some efficacy or effectiveness data are available. The stronger the data are in a given area, the stronger we can make this recommendation. Even in areas in which ACT can cautiously be considered a front line treatment, however, sometimes it has less support than some other models at this point so consider these seriously before deciding to proceed and make sure evaluation is on-going.

This table lists only published data though if additional major studies are coming and we have actually seen the data in detail they may be mentioned as well. We have divided the data into randomized controlled trials and other types of studies – e.g., pre-post designs or single case designs. Only outcomes studies with real patients are included, not analogs. See the publications page for detailed information. This table is current as of early 2011 but the literature is moving very quickly and it takes a while to update pages like this. To be honest, as the literature gets larger and larger head counts of studies starts to seem obsessive so it could be that this Table will be rarely updated and you will have to check the list of actual controlled studies to see if there are studies that fit your interest.  For a more detailed list of outcome studies and other empirical research you can also download the “ACT handout” in the research resources page or check the other research summaries posted on the website, which are updated regularly.

ACT Data

Depression 5 RCTs; 3 other. Some indication that it is superior to CBT in some settings. Evidence of a distinct process.
Anxiety / Stress / OCD 9 RCTs; 11 other. Data supporting the application of ACT with a number of different problems related to anxiety and stress. Some indication that it is superior to CBT in some settings, but also data that it can be beaten by traditional BT in minor anxiety problems. Evidence of changes in ACT processes mediating outcomes.
Psychosis 3 RCTs; 5 other. Not yet compared to other psychosocial methods beyond support but effects are good for amazingly small interventions. Done in addition to antipsychotic medication. Mediated by ACT processes.
Substance abuse 3 RCTs; 3 other. Some indication that it does better than existing pharmacotherapy methods, or supplements their effects.
Smoking 3 RCTs; 2 other. Indication that it does better than existing pharmacotherapy methods, or supplements their effects.
Chronic Pain 3 RCTs; 7 other, including three decent sized effectiveness trials. Good outcomes. No good head to head comparisons with empirically supported alternative methods yet. Works through ACT relevant processes.
Prejudice and burn out 3 RCTs; 1 crossover. Beats multicultural counseling and education alone. Works through ACT relevant processes. Helps in both stigma and burnout. Other good studies completed and on the way.
Marital problems 1 other. Very limited data.
Eating disorder or body dissatisfaction 2 RCTs; 1 other.
Sexual deviation 2 other. Very limited data.
Dually diagnosed 1 RCT (sub-analysis). 1 other. Promising but limited data.
Self Harm / BPD 2 RCTs, one that mixed ACT with DBT. Good outcomes. Limited follow up. Did move ACT relevant processes.
Epilepsy 3 RCTs. Good outcomes on both seizures and quality of life. 1 year follow up. Mediated by ACT processes.
Diabetes management 1 RCT. Good outcomes at follow up on self management and glucose control. Mediated by ACT processes.
Weight maintenance 2 RCTs. Good outcomes which were mediated through ACT processes.
Augmenting training in other therapies 2 RCTs. Found ACT can increase the adoption of evidence-based psychotherapy methods by clinicians and is mediated through ACT processes.
Coping with cancer 3 RCT; 1 Other. Preliminary data suggests ACT can improve coping with cancer. One RCT shows ACT is more helpful than traditional CBT elements in dealing with end stage cancer and works through a different process.
Sports performance 3 Other. Very limited data suggesting ACT can improve performance in various sports.

There are some data on effectiveness (see the “publications” section and effectiveness study summary page). Thus, we feel that we can recommend ACT to systems of care provided they use it under the limitation suggested above and will work with us to train it properly, and to evaluate its impact.