Institute for Public Health and the Environment (RIVM) Sweden Association of Physiotherapists SAMHSA's National Registry of Evidence-based Programs and Practices California Evidence-Based Clearinghouse for Child Welfare U.S. Department of Veterans Affairs/Department of Defense History In 2006, only about 30 randomized clinical trials and controlled time series evaluating ACT were known, but in 2011 the number had approximately doubled. A 2008 meta-analysis concluded that the evidence was still too limited for ACT to be considered a supported treatment. A 2009 meta-analysis found that ACT was more effective than placebo and "treatment as usual" for most problems (with the exception of anxiety and depression), but not more effective than CBT and other traditional therapies. A 2012 meta-analysis was more positive and reported that ACT outperformed CBT, except for treating depression and anxiety. A 2015 review found that ACT was better than placebo and typical treatment for anxiety disorders, depression, and addiction. Its effectiveness was similar to traditional treatments like cognitive behavioral therapy (CBT). The authors also noted that research methodologies had improved since the studies described in the 2008 meta-analysis. In 2020, a review of meta-analyses examined 20 meta-analyses that included 133 studies and 12,477 participants. The authors concluded ACT is efficacious for all conditions examined, including anxiety, depression, substance use, pain, and transdiagnostic groups. Results also showed that ACT was generally superior to inactive controls, treatment as usual, and most active intervention conditions. In 2020–2021, after three RCTs of ACT by the World Health Organization (WHO), WHO released an ACT-based self-help course for "groups of up to 30 people who have lived through or are living through adversity". In 2022, a systematic review of meta-analyses about interventions for depressive symptoms in people living with chronic pain concluded that ACT for general chronic pain "showed the most robust effects and can be prioritized for implementation in clinical practice". Professional organizations The Association for Contextual Behavioral Science is committed to research and development in the area of ACT, RFT, and contextual behavioral science more generally. As of 2021 it had over 9,000 members worldwide, about half outside of the United States. It holds annual "world conference" meetings each summer, with the location alternating between North America and Europe. The Association for Behavior Analysis International (ABAI) has a special interest group for practitioner issues, behavioral counseling, and clinical behavior analysis ABA:I. ABAI has larger special interest groups for autism and behavioral medicine. ABAI serves