Conceptual, Psychometric, Methodological and Value Problems in Acceptance and Commitment Therapy: Introduction to the Special Section, "A Critical Appraisal of Acceptance and Commitment Therapy".

There is a voluminous and expanding literature regarding ACT, from descriptions of its theory to its stated roots in relational frame theory, the particulars of its therapy techniques and exercises, favored metaphors, randomized controlled trials, to many self-help books for a wide variety of problems. The therapy is widely marketed through workshops and many self-help books. ACT is associated with its own journal and its own professional organization, the Association for Contextual Behavioral Science (ACBS). This literature is interpreted by ACT proponents as demonstrating the causal efficacy of ACT for a wide range of problems and, at times, even being superior to treatment as usual, which are often more traditional forms of cognitive behavior therapy (CBT). This special section contains a series of 6 papers examining these claims. Correctly understanding and evaluating the claims of ACT proponents is warranted because these can have direct implications for treatment decisions by therapists attempting to deliver the most effective treatment for their clients' problems. The papers, individually and as a whole, urge considerable caution, particularly because much of its research has involved serious measurement problems, problematic research designs, and a unique and problematic conceptualization and perhaps the practice of values and ethics. These papers call for methodological improvements and a commitment to more traditional values associated with science so that ACT can be more fairly evaluated to accurately understand its assets and limitations.