Home › ACT › Research Resources and Publications

State of the ACT Evidence

July 15, 2008 - 2:56pm — Steven Hayes

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 recent (July 2008) PowerPoint presentation of the evidence can be downloaded above. Also above is a table showing effect sizes for the ACT outcome literature. The most recent 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.

ACT is not yet formally an empirically supported treatment on EST lists, though it is approaching or perhaps exceeding the standards for that status in some areas, such as smoking, pain, and psychosis, awaiting appearance of publications in press or under submission and on review by authorities responsible for such lists.

We recommend ACT 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 ESTs 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, the stronger we can make this recommendation.

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. "Published" data include theses and dissertations. See the publications page for detailed information. This table is current as of July 2008 but the literature is moving quickly and it takes a while to update pages like this. For a more detailed list of outcome studies and other empirical research you can download the "ACT Handout" and/or check the research summaries posted on the website, which are updated regularly:

ACT Data

Depression 4 RCTs; 3 other. Some indication that it is superior to CBT in some settings. Evidence of a distinct process.
Anxiety / Stress / OCD 4 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.
Psychosis 2 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 2 RCTs; 3 other. Some indication that it does better than existing pharmacotherapy methods, or supplements their effects.
Smoking 2 RCTs; 1 other. 1 other RCT under review also found good outcomes. Indication that it does better than existing pharmacotherapy methods, or supplements their effects.
Chronic Pain 2 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 2 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 1 other. Very limited data.
Sexual deviation 2 other. Very limited data.
Dually diagnosed 1 RCT (sub-analysis). 1 other. Promising but limited data.
Self Harm / BPD 1 RCT that mixed ACT with DBT. Extremely good outcomes but no follow up. Did move ACT relevant processes.
Epilepsy 2 RCTs. Very 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 1 RCT. 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 1 RCT; 1 Other. Preliminary data suggests ACT can improve coping with cancer. One other completed RCT shows ACT is more helpful than traditional CBT 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.