A Meta-analytic Review of Acceptance-based Behavioral Interventions for the Treatment of Anxiety


David Shanley

Date of Award


Document Type

Undergraduate Capstone Project

Degree Name


Organizational Unit

Graduate School of Professional Psychology

First Advisor

John McNeill

Second Advisor

Peter Buirski

Third Advisor

Arnica Buckner


Acceptance and commitment therapy, Quantitative research, Behavior CBT, Meta-analytic review, Acceptance


The relative popularity of acceptance and commitment therapy (ACT) has grown in recent years, and inspired the development of contemporary acceptance-based treatment approaches. Acceptance-based therapies differ from traditional cognitive- behavior therapy (CBT) on pragmatic grounds, the import of which implicates the purpose of therapy. CBT utilizes exposure and cognitive change techniques primarily in service of symptom change outcomes; whereas, ACT utilizes exposure and acceptance for purposes of promoting psychological flexibility in the pursuit of personal values. The purpose of this meta-analytic study was to determine the relative efficacy of acceptance- based versus symptom-change behavioral approaches with anxiety disorders and to quantify this impact. A comprehensive literature search turned up 18 studies that met inclusion criteria for this analysis. An effect size was calculated using the standardized mean gain procedure for both the acceptance-based and symptom-change approaches, along with the waitlist control groups. The results demonstrate a large effect size for the acceptance-based approach (Weighted mean ES = .83) and a medium effect size for symptom-change approach (Weighted mean ES = .60). The waitlist control groups demonstrated a small effect size (Weighted mean ES = .24). Based on this review, it is suggested that graduate and internship programs in Clinical Psychology should promote evidence-based training in the use of acceptance-inspired behavioral therapies.

Publication Statement

Copyright is held by the author. Permanently suppressed.


40 pages

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