There are now over 900 randomized controlled trials demonstrating the positive effects of Acceptance and Commitment Therapy (ACT) for a wide range of areas. ACT is listed as an empirically supported therapy for multiple clinical concerns and is being disseminated as an evidence-based treatment by organizations including the United States Veterans Health Administration and the World Health Organization.
In The Oxford Handbook of Acceptance and Commitment Therapy, Michael P. Twohig, Michael E. Levin, and Julie M. Petersen bring together contributions from the world's leading scholars to create a comprehensive volume on established areas of ACT. The Handbook presents a scholarly review of the treatment as it has developed over the past two to three decades. Featuring 33 chapters on key aspects of the treatment, the contributors offer analysis on ACT's conceptual and theoretical underpinnings, applications to specific populations and problems, methods of implementation, and other special topics. They further cover theory, empirical support, and scholarly descriptions of treatment application. The volume is divided into four sections, with the first, on conceptual foundations, offering five chapters that comprise a primer on ACT. The second section presents chapters on ACT methods, such as acceptance, cognitive defusion, and values. The third section covers specific applications of ACT, including depression, eating disorders, and psychosis. The fourth and final section covers issues implementing ACT such as training, delivery in schools, technology, and cultural adaptation. The Handbook concludes with two chapters examining directions for future research and practice.
Offering rich resources to further study each topic, the Handbook is an essential resource for scholars and students who wish to understand the important major aspects of this transdiagnostic form of cognitive behavior therapy.

Michael P. Twohig, Ph.D., is a licensed psychologist in the state of Utah and a Professor of Psychology at Utah State University, where he co-runs the ACT Research Group (with Dr. Levin). He received his B.A. and M.S. from the University of Wisconsin-Milwaukee, his Ph.D. from the University of Nevada, Reno, and completed his clinical internship at the University of British Columbia Hospital. He is past-President of the Association of Contextual Behavioral Science, the organization most associated with Acceptance and Commitment Therapy (ACT). His research focuses on the use of ACT across a variety of clinical presentations with an emphasis on obsessive compulsive and related disorders. He has published over 200 scholarly works including 5 books, with the most recent being Innovations in ACT (with Levin and Krafft) and ACT in Steps (with Levin and Ong). His research has been funded through multiple sources including the National Institute of Mental Health.
Michael E. Levin, Ph.D., is a Professor in the Department of Psychology at Utah State University and co-directs the ACT Research Group with Dr. Twohig. He received his Ph.D. in Clinical Psychology from the University of Nevada, Reno under the mentorship of Dr. Steven C. Hayes and completed his predoctoral internship at the Brown University Clinical Psychology Training Consortium. Dr. Levin's research focuses on internet-based ACT interventions for a range of mental health and chronic health conditions. He has published over 100 peer-reviewed articles, primarily on ACT and self-guided interventions delivered through websites, apps, and books. Dr. Levin is also a Fellow of the Association for Contextual Behavioral Science and Editor-in-Chief for the Journal of Contextual Behavioral Science.
Julie M. Petersen, M.S., is a doctoral student in the combined clinical/counseling psychology program at Utah State University. She received her B.S. in psychology from Haverford College in 2016. Before coming to USU, she worked as a research assistant at the University of Pennsylvania's Center for the Treatment and Study of Anxiety. Her research interests are centralized around the treatment of obsessive-compulsive and anxiety disorders, particularly for kids and teens. She has published more than 20 articles and book chapters related to ACT, and has collaborated with Levin and Twohig on numerous research studies and projects related to ACT.

Section 1: Conceptual foundation
Chapter 1: Progression of ACT
Robert Zettle, Ph.D. & Kelly Wilson, Ph.D.
Chapter 2: Implementing ACT as Contextual Behavioral Science
Emily K. Sandoz, Ph.D. & Caleb Fogle
Chapter 3: Primer on Basic Behavioral Principles
Tom J. Waltz, Ph.D., & Claudia Drossel, Ph.D.
Chapter 4: A Primer on Relational Frame Theory (RFT)
Colin Harte, Ph.D., & Dermot Barnes-Holmes, Ph.D.
Chapter 5: Clinical Behavior Analysis and RFT: Conceptualizing Psychopathology and its Treatment
Carmen Luciano, Ph.D., Niklas Törneke, M.D., & Francisco J. Ruiz, Ph.D.
Section 2: General ACT Methods
Chapter 6: An ACT Approach to Assessment, Case Conceptualization, and Treatment
Katrina M. Daigle, Mikala A. Grimaldi, Rebecca L. Schneider, Ph.D., & Lisa W. Coyne, Ph.D.
Chapter 7: Psychological Flexibility
Clarissa W. Ong, M.S. & Elizabeth H. Eustis, Ph.D.
Chapter 8: Acceptance
Rhonda M. Merwin, Ph.D., Ashley A. Moskovich, Ph.D., Angela Pisoni, M.A., Sara Freeman, M.A., & Carly Onnink, B.S.
Chapter 9: Cognitive Defusion
Francisco J. Ruiz, Ph.D., Barbara Gil-Luciano, & Miguel A. Segura-Vargas
Chapter 10: Present Moment Awareness
Matthew S. Herbert, Ph.D. & Niloofar Afari, Ph.D.
Chapter 11: Self-as-Context
Louise McHugh, Ph.D. & Alison Stapleton
Chapter 12: Values in Acceptance and Commitment Therapy
Jenna LeJeune, Ph.D. & Jason Luoma, Ph.D.
Chapter 13: Committed Action
Lance M. McCracken, Ph.D.
Section 3: Specific applications of ACT
Chapter 14: Depression
Jacqueline A-Tjak, Ph.D. & Louise Hayes, Ph.D.
Chapter 15: ACT for Anxiety and Trauma-Related Disorders
Brooke Smith, Ph.D., Gregory S. Smith, & Ellen J. Bluett
Chapter 16: Obsessive Compulsive and Related Disorders
Eric B. Lee Ph.D., Myles Arendtson, B.A., & Andy Wall, B.S.
Chapter 17: Eating Disorders
Adrienne Juarascio Ph.D., Paakhi Srivastava, Ph.D, Christina Felonis, & Olivia Wons
Chapter 18: Health Promotion and Weight Management for Obesity
Jason Lillis, Ph.D. & Dayna Lee-Baggley,Ph.D.
Chapter 19: Acceptance and Commitment Training in the Workplace
Paul E. Flaxman, Ph.D., Arianna Prudenzi, & Lucie Zernerova
Chapter 20: Acceptance and Commitment Therapy for Chronic Pain
Karlyn A. Edwards, M.S. & Kevin E. Vowles, Ph.D.
Chapter 21: ACT for Chronic Health Condition
Lilian Dindo, Ph.D, Julia R. Van Liew, Ph.D., & Joanna J. Arch, Ph.D.
Chapter 22: Acceptance and Commitment Therapy (ACT) for Substance Use
Maria Stavrinaki, Ph.D., Megan M. Kelly, Ph.D., & Maria Karekla, Ph.D.
Chapter 23: ACT for Smoking Cessation
Jonathan B. Bricker, Ph.D.
Chapter 24: ACT for the Treatment of Psychosis and Schizophrenia-Spectrum Disorders
Brandon A. Gaudiano, Ph.D. & Stacy Ellenberg, M.S.
Section 4: Implementation of ACT
Chapter 25: Effective Training and Delivery of ACT: The Dissemination and Implementation Issues
Robyn D. Walser, Ph.D. & Emily Wharton, M.S.
Chapter 26: ACT in Schools: A Public Health Approach
Tyler L. Renshaw, Ph.D., Sean N. Weeks, Anthony J. Roberson, Ph.D., & Stephanie A. Vinal, M.A.
Chapter 27: ACT for Children and Adolescents
Julie M. Petersen, Louise Hayes, Ph.D., Duncan Gillard, D Ed Psy,& Joseph Ciarrochi, Ph.D.
Chapter 28: Technology
Raimo Lappalainen, Ph.D., Katariina Keinonen, Ph.D., & Päivi Lappalainen, Ph.D.
Chapter 29: ACT in Groups
Joanna J. Arch, Ph.D., Lauren B. Finkelstein, & Lilian Dindo, Ph.D.
Chapter 30: Cultural Adaptations of Acceptance and Commitment Therapy
Aki Masuda, Ph.D., Lucas Morgan, Ph.D., Samuel D. Spencer, M.A., Joanne Qina'au, M.A., & Duckhyun Jo, M.A.
Chapter 31: Acceptance and Commitment Therapy Inside Behavior Analysis
Jonathan Tarbox, Ph.D., Amanda N. Chastain, & Thomas G. Szabo Ph.D.
Conclusion
Chapter 32: Future Directions of Contextual Behavioral Science
Rikard Wicksell, Ph.D., Niklas Törneke, Lance McCracken, Jonathan Bricker, Amy Murrell, Aki Masuda, & Tony Biglan
Chapter 33: Creating Progress in Contextual Behavioral Science:Overcoming the Hurdles of the Past, Facing the Challenges of the Future
Neal Falletta-Cowden, Steven C. Hayes, & Michelle Forman
Index