© 2014 COPYRIGHT PHYSICIANS POSTGRADUATE PRESS, INC. NOT FOR DISTRIBUTION, DISPLAY, OR COMMERCIAL PURPOSES. e695 J Clin Psychiatry 75:7, July 2014 Meta-Analysis A Meta-Analysis of Computerized Cognitive-Behavioral Therapy for the Treatment of DSM-5 Anxiety Disorders Caroline B. Adelman, PhD; Kaitlyn E. Panza, BA; Christine A. Bartley, BA; Allyson Bontempo, BA; and Michael H. Bloch, MD, MS ABSTRACT Objective: Access to qualified cognitive-behavioral therapy (CBT) remains a major barrier to improving clinical outcomes in anxiety disorders. The current meta-analysis examined the efficacy of computerized CBT (cCBT) for anxiety disorders and the durability of treatment gains during follow-up. Data Sources: We searched PubMed and references from included trials and previous meta-analyses in the area. Study Selection: We included randomized controlled trials assessing the efficacy of cCBT for non-OCD and non-PTSD anxiety disorders. Data Extraction: Forty trials involving 2,648 participants were included in this meta-analysis. We used a fixed- effect model to examine standardized mean difference in posttreatment anxiety levels. cCBT was compared to wait-list, in-person CBT, and Internet control. We also examined moderators of cCBT treatment gains over follow-up. Results: Meta-analysis indicated that cCBT was significantly more effective than wait-list control in the treatment of anxiety disorders (standardized mean difference [SMD] = 0.92 [95% CI, 0.83 to 1.02], k = 31, z = 18.8, P < .001). Moderator analyses also found that cCBT targeting specific anxiety disorders had greater efficacy than that targeting mixed anxiety symptoms. The efficacy of cCBT was equivalent to in-person CBT in studies that compared them head-to-head, for both children and adults (SMD = 0.05 [95% CI, -0.09 to 0.19], k = 15, z = 0.7, P = .46). Longitudinal studies indicate that individuals undergoing cCBT tended to continue to improve after completion of treatment, with longer follow-up periods associated with greater symptom reduction. Conclusions: cCBT represents an efficacious intervention for the treatment of anxiety disorders and may circumvent barriers to accessing traditional CBT treatments. Further research is needed to examine the effectiveness of cCBT in real-world settings, for individuals with clinical comorbidities, and in comparison with more ecologically valid comparison conditions. J Clin Psychiatry 2014;75(7):e695–e704 © Copyright 2014 Physicians Postgraduate Press, Inc. Submitted: November 19, 2013; accepted March 11, 2014 (doi:10.4088/JCP.13r08894). Corresponding author: Michael H. Bloch, MD, MS, Child Study Center, Yale University School of Medicine, PO Box 2070900, New Haven, CT 06520 (michael.bloch@yale.edu). A nxiety disorders represent a significant public health concern, affecting an estimated 21% of adults and 25% of adolescents in the United States each year. 1 Left untreated, anxiety disorders are likely to persist 2 and represent a risk factor for the development of other psychological disorders, including depression and substance abuse. 3 Fortunately, anxiety disorders are highly responsive to treatment. Cognitive-behavioral therapy (CBT) is an effective treatment for anxiety disorders, 4 with a majority of individuals showing clinically significant symptom reduction following engagement in CBT. 5 Despite the proven effectiveness of cognitive-behavioral interventions, many individuals with anxiety disorders never seek appropriate professional treatment. 6,7 Those who do seek treatment for anxiety disorders often wait years to do so, with the median delay in treatment seeking in the United States estimated to be 23 years after symptom onset. 8 Commonly cited barriers to treatment- seeking include perceived stigma, high costs, lack of insurance, poor access to treatment in rural or remote regions, and a relative dearth of clinicians qualified to provide CBT for anxiety disorders. 9 In response to evidence that such factors may limit treatment access, there has been a surge of interest in computer-based cognitive- behavioral therapy (cCBT) for anxiety disorders. Computerized treatments typically provide time-limited, manualized CBT interventions, via Internet or computer software, with varying levels of therapist involvement. Because they are accessible to anyone with a computer and an Internet connection, computer-based CBT programs provide one promising solution to increase access to effective treatment for anxiety disorders. Computer-based cognitive- behavioral therapy can be delivered to individuals living in remote regions, does not rely on the local availability of skilled clinicians, can be significantly more cost-effective than traditional CBT, and can circumvent concerns related to perceived stigma. Dozens of studies have been conducted over the past decade to determine the feasibility and effectiveness of cCBT for anxiety disorders. 10,11 These studies have varied widely in their quality, focus, sample size, and methodology, resulting in ongoing uncertainty regarding the true effectiveness of computer-based interventions for anxiety disorders. An updated, systematic meta-analysis of randomized controlled trials (RCTs) is needed to determine the true effectiveness of computer-based cognitive-behavioral treatment of anxiety disorders among both children and adults. Additionally, meta-regression can be an effective method to examine moderating factors that may influence reported efficacy of treatment. Although at least 3 comprehensive meta-analyses of cCBT for anxiety disorders have been conducted in recent years, 12–14 the number of RCTs examining cCBT for anxiety disorders has nearly doubled since 2010, making previously underpowered moderator analyses now feasible. Furthermore, the exclusion of obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) from