The CBS tradition 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 and evolutionary science principles, including those drawn from RFT. As the best known applied wing of CBS, all of these features are important to ACT research.
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 including evidence on measures and processes of change
3. Links to various summaries of particular kinds of research
This page is normally updated every month. The date of last update: August 2021. If you are aware of missing data, please contact the ACBS staff: acbsstaff@contextualscience.org or send a note to missing.studies@gmail.com
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. The World Health Organization
Pain (Children and Adolescents) - WHO lists ACT as empirically supported ("moderate certainty") in the reduction of functional disability in children and adolescents with chronic pain (click here for the report).
Based on several successful randomized trials it conducted with South Sudanese and Syrian war refugees, WHO also now distributes ACT-based self-help for free in 21 languages and says on its website that ACT self-help is good for “anyone who experiences stress, wherever they live, and whatever their circumstances.” (click here for the free program)
ii. 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
iii. California Evidence-Based Clearinghouse for Child Welfare (click here for the report)
Depression Treatment (Adult) - Scientific Rating 1 (Well Supported by Research Evidence)
iv. U.S. Dept of Veterans Affairs / U.S. Dept of Defence (click here for the report)
Clinical Practice Guideline for the Management of Major Depressive Disorder
v. US Department of Justice - Office of Justice Programs (click here for the report)
ACT for Partner Aggression: Evidence Rating: Effective
vi. Washington State Institute for Public Policy - WSIPP systematically assesses all high-quality studies from the United States and elsewhere to identify evidence based policy options that have been tested and found to achieve improvements in outcomes.
Schizophrenia/psychosis
Adult anxiety
Children with anxiety
Children with depression
vii. Title IV-E U.S. Department of Health and Human Services (HHS) Prevention Services Clearinghouse (under review, 2021: mental health; substance use).
viii. SAMHSA's National Registry of Evidence-based Programs and Practices, ACT, last review July 2010. (NREPP has since been shut down, so this will not be updated unfortunately)
ix. The UK National Institute for Health and Care Excellence (NICE)
Pain - NICE recommends ACT for people aged 16 years and over with chronic primary pain. (click here for the full report).
Tinnitus - NICE recommends group-based ACT for tinnitus-related distress. (click here for the full report).
x. Australian Psychological Society, Evidence Based Psychological Interventions in the Treatment of Mental Disorders (2018):
Adults
Anxiety disorders - Generalised anxiety disorder – Level II Evidence
Anxiety disorders - Social anxiety disorder – Level II Evidence
Anxiety disorders - Panic disorder – Level II Evidence
Borderline personality disorder – Level II Evidence
Depression – Level II Evidence
Hypochondriasis – Level II Evidence
Obsessive compulsive disorder – Level II Evidence
Pain Disorders – Level II Evidence
Psychotic disorders – Level II Evidence
Substance use disorders – Level II Evidence
Binge eating disorder – Level IV Evidence
Body dysmorphic disorder – Level IV Evidence
Children (age 10-14 years)
Pain Disorders – Level II Evidence
xi. Netherlands Institute of Psychologists: Sections of Neuropsychology and Rehabilitation, Richtlijn Neuropsychologie Revalidate (2017)
The Netherlands Institute of Psychologists (NIP) recommends ACT for patients with MS with depressive symptoms
xii. Netherlands National Institute for Public Health and the Environment, Rijksinstituut voor Volksgezondheid en Milieu (RIVM) (2020)
The Netherlands National Institute for Public Health and Environment (RIVM) states "Voluit Leven" has strong evidence of effectiveness and is primarily intended for adults with mild to moderate depression symptoms. The intervention "Voluit Leven" is based on Acceptance & Commitment Therapy and has been spatially researched and found to be effective both nationally and internationally.
xiii. Sweden Association of Physiotherapists,Fysioterapi Profession och vetenskap (2016)
The Swedish Association of Physiotherapy (physical therapy) includes ACT as a physiotherapeutic theory and practice in the definition of the profession.
xiv. American Headache Society, The American Headache Society Consensus Statement: Update on integrating new migraine treatments into clinical practice (2021)
2. Peer reviewed assessments of the ACT evidence base
A list of meta-analyses, systematic or narrative reviews of the ACT evidence base, either overall or in specific areas, can be found here. (a child page to this webpage). The list is presented in reverse chronological order, by year of publication. There are now a handful of meta-analyses of meta-analyses (e.g., Gloster et al., 2020) -- a kind of a super summary. As of mid 2023, there are over 440 meta-analyses, systematic reviews, and narrative reviews on the list and it is growing very rapidly..
3. Mediational analyses
ACT is a process-oriented approach and the list of studies testing mediation or moderation is quite large. This list is rapidly growing. A partial list can be found here (a child page to this webpage). A recent review of the entire world's literature of successful mediational analyses of all forms of psychosocial intervention for mental health outcomes found that psychological flexibility (including closely related concepts such as mindfulness) accounted for well more than half of all replicated research findings (https://pubmed.ncbi.nlm.nih.gov/35863243/).
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. Thus qualitative work has been important in the ACT journey from the beginning.
Qualitative work is hard to do but it has continued throughout the ACT research program. Examples can be found here (a child page to this webpage). If you find any more send them to ACBS staff to add to the list.
5. ACT Randomized Controlled Trials
Click here for details of each of these ACT RCT studies, along with links to the original research articles. As of mid 2023 there are nearly 1,050 ACT randomized controlled trials.
Click here for the Snapshots of the ACT RCT Evidence Base subject guide (last updated December 2019). Updating this list becomes more difficult as the list expands rapidly but a team is working on a new and comprehensive summary which we hope will be available in late 2023.
6. Negative Findings
It is important to consider negative findings to learn from mistakes and to improve methods. For many years we have listed negative findings here on our website. See the daughter page to this page for examples, but look also at the meta-analysis page. There is clear evidence of moderation in several areas of research in which ACT is not at good as other methods with some persons and perhaps better than these same methods with other persons. It is also important to look over time to see if deficiencies grow or are ameliorated. Note the differences between non-superiority and outright negative findings. And consider the individual and look for studies that go beyond averages to carefully document for whom ACT methods are helpful and for whom they are not. Terms like "non-responders" will help dive into these issues more deeply.