**2. Literature review**

**1. Introduction**

practice for some patients.

202 Cognitive Behavioral Therapy and Clinical Applications

receive adequate psychotherapy or counseling [4].

health centres, let alone… primary care clinics" [8].

compared with traditional CBT (a literature review follows).

• Strong evidence from controlled randomized trials shows that iCBT can be used in clinical

• Practical considerations suggest that some forms of iCBT are more effective than others.

Mental disorders are disabling and common. Depression, for example, has greater global burden of disease than any physical disorder [1]. 29% of people will experience some form of mental disorder in their lifetime [2]. Yet care is often difficult to access: only 45% of people in developed countries receive care, and the percentage of people who receive treatment is just 15% in developing countries [3]. Even when patients have access to mental healthcare, it may be inadequate. In North America, between 30 and 79% of patients treated for depression receive sub-standard treatment. In a study of patients in British Columbia, Canada, who received treatment for depression, Puyat et al. found that only 13% received any psychotherapy or counseling; women, older patients, and patients in rural areas were less likely to

Cognitive Behavioral Therapy (CBT) is an evidence-based treatment. Beck's Cognitive Triad, the conceptual basis of CBT, is built on the principle that people's thoughts, emotions, and behaviors are connected. By taking control of their thoughts, patients can reframe how they interpret the events around them [5]. CBT has been shown to be equivalent to medication for mild and moderate anxiety and depression. Combining psychopharmacology with CBT may have a synergistic effect [6]. However, CBT requires time and resources, which partly explains its limited availability, even in public healthcare systems like Canada's. Therefore, many primary care physicians and psychiatrists do not offer CBT [7]. As a recent JAMA Psychiatry editorial noted: "Traditionally, psychotherapy developers focused on interventions for specific diagnoses to be implemented by mental health professionals in mental health settings. Once established as evidenced based, these therapies often failed to be disseminated into mental

While access to mental healthcare is not always available, more and more people have access to the Internet and smartphones, even in the developing world [3]. CBT is a good intervention for technology-based applications because the concepts are easily adapted into broadly applicable sessions (or modules) that can be distributed by email, the web, or apps [9]. Not surprisingly, numerous programs have been developed. Studies show Internet-assisted CBT (or iCBT) is cost-effective for patients; it is also more convenient for patients and providers

In this chapter, we will look at the effectiveness of iCBT for several illnesses, based on new evidence from recent randomized controlled trials and meta-analyses. We consider iCBT in the real world, by looking at some popular apps and websites. We present a case from a Canadian

• Further experimentation, including with AI, has the potential to re-shape therapy.

**1.1. Key points**

iCBT continues to be a hot area of research in psychiatry. A PubMed search of "Internet cognitive behavioral therapy" yielded over 1600 articles, about 300 more than a search conducted just 2 years ago [9]. The literature has been reviewed extensively by ourselves and others [9–18]. Among the best-studied interventions are those for depression, anxiety, and physical illness. Presented here are some of the most recent systematic reviews, meta-analyses, and randomized controlled trials about treatment effectiveness and address some of the most pressing concerns and promising developments in the new field of iCBT.
