**1. Introduction**

In recent decades, technological developments have significantly changed people's lives. The pervasiveness of technology has impacted almost every aspect of living in the modern world. Countless examples are illustrative of this influence, including almost complete automation of many communication tasks through e-mail, instant messaging, etc. This technological revolution has impacted how we socialise, shop, bank, learn, travel, and live our lives. The changes that these developments have delivered have been massive and have not gone unnoticed by health care professionals.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Cognitive behaviour therapy (CBT) is the most widely researched and established evidencebased treatment for psychological disorders [1]. In recent years, internet-delivered cognitive behaviour therapy (iCBT) interventions have become a method for the dissemination of evidence-based treatments for a broad range of psychological disorders including depression and anxiety. More recently, iCBT is being used to address the psychological distress associated with the management of long-term conditions in individuals with, for example, diabetes, coronary heart disease, and chronic pain.

in the number of published reports that support iCBT for a broad range of psychological disorders. Most notably, clinical trials have established a sound empirical base for the treatment of the major depressive disorder and a range of anxiety disorders (social anxiety, panic disorder, and generalised anxiety disorder) and emerging evidence for others (severe health anxiety, specific

Internet-Delivered Cognitive Behaviour Therapy http://dx.doi.org/10.5772/intechopen.71412 225

Given the high prevalence of depression and anxiety disorders and their global ubiquity, interest on iCBT has grown due to its potential to support the dissemination of evidencebased CBT. It is fair to say that internet-delivered cognitive behaviour therapy interventions find their historical roots in the treatment of depression and anxiety disorders. Several metaanalytic studies have now demonstrated the efficacy of iCBT for depression. The earliest of these studies included computerised and internet-delivered interventions, and consistently reported the same results that iCBT is effective as an intervention for the treatment of depression. Andersson and Cuijpers [8] examined a group of 12 studies and reported an overall post-treatment effect size of *d* = 0.41versus control groups. Their analysis showed that the effect size estimate was moderated significantly between supported (*d* = 0.61) and unsupported (*d* = 0.25) treatments. Another systematic review and meta-analysis conducted by Richards and Richardson [9], examined the efficacy of computer-based psychological interventions for depression and concluded that, while the outcomes of computer-assisted interventions for depression are generally positive, these results also vary depending on the type of support provided throughout the intervention. Specifically, therapist-supported studies demonstrated the highest effect size at post-treatment and follow-up (*d* = 0.78), followed by administrative-supported studies (*d* = 0.58); that is, the non-therapeutic support provided. Interventions that did not include a support component obtained the lowest estimated effect size (*d* = 0.36). The results support the inclusion of any form of support, either a professional therapist, or a trained para-professional, or indeed a trained peer volunteer, or technician, as beneficial for optimising the efficacy of iCBT interventions [5, 10, 11]. Also, a recent individual service user data meta-analysis has shown that adherence to treatment predicts better

The ability of internet-delivered interventions to maintain clinical gains at follow-up can contribute significantly towards their acceptability, adoption, and implementation in clinical practice. Many trials incorporated follow-up to 6- or 12-months post-treatment [13–15], demonstrating that iCBT has the potential to achieve and maintain significant clinical gains for service users. A smaller number have shown lasting impacts up to 3-years post-treatment [16, 17]. In one non-inferiority controlled trial of iCBT for depression that included a face-to-face control group, 3-year follow-up data demonstrated sustained improvements for both groups,

Achieving outcomes that are similar to what has been offered in face-to-face treatments for depression only strengthens the validity of iCBT interventions for depression. A small number of trials have attempted this comparison, and in a review of this work, the authors [18] concluded that any differences were non-significant. In fact, they report that the effect size (*g* = 0.12) favoured the supported iCBT over the face-to-face interventions. What is not clear and requires further attention is whether the mechanisms of change that facilitate the success

of face-to-face interventions are equally relevant in iCBT interventions [19].

phobias).

outcomes [12].

with no significant differences between them [16].

The first complete cognitive behaviour therapy (CBT) treatment was delivered through the use of compact disc-read only memory (CD-ROM) that contained the full programme, such as Beating the Blues. As technology developed and the web evolved, such treatments were offered entirely online, thus heralding the dawn of internet-delivered interventions (e.g., MoodGym). The majority of internet-delivered interventions deliver cognitive behaviour therapy (CBT)-based treatments, as it is a structured and modular-based treatment that lends itself readily to being repurposed into an online format.

Internet-delivered treatments are named variously as online interventions, web-based interventions, e-therapy, e-health, and computerised cognitive behaviour therapy (cCBT) [2]. Some of the developments in the field have used brand names such as Interapy for PTSD [3], Deprexis for depression [4], and SilverCloud for depression, anxiety, and long-term conditions management [5]. Technology-delivered psychological interventions have a rich history, and it is still very much a developing field of study and clinical practice.

Results profit from many features and benefits of web development and design, where CBT protocols have been repurposed for use online. These features include the use of multimedia, open and unlimited access to the intervention, as well as delivering a secure platform, which protect the service users' confidentiality and data. Internet-delivered treatments place the pace and direction of the treatment in the hands of the service users and reduce the burden on therapists' time. The capacity to deliver evidence-based treatment protocols in this way could have enormous impact on healthcare provision into the future, some of which we have already seen today.

This chapter focuses on internet-delivered cognitive behaviour therapy (iCBT) interventions for depression and anxiety as a way of illustrating the field of internet interventions. It will describe their development, adoption, and implementation in various settings, including, for example, healthcare and employee assistance programmes. We begin by summarising the empirical evidence that supports the use of iCBT interventions for depression and anxiety disorders. After that, we will describe iCBT interventions function in practical terms. This description will illustrate using a case study example. Service delivery examples follow, which help demonstrate the flexible use of iCBT in various settings. The chapter will end by addressing future directions for both academic study and the practical implementation of iCBT.
