User Experience of Cognitive Behavioral Therapy Apps for Depression: An Analysis of App Functionality and User Reviews

Background: Hundreds of mental health apps are available to the general public. With increasing pressures on healthcare systems. they offer a potential way for people to support their mental health and well-being. However, while many are highly rated by users, few are evidence-based. Equally, our understanding of what makes apps engaging and valuable to users is limited. Objective: The aim of this paper was to analyse functionality and user opinions of mobile applications (apps) purporting to support Cognitive Behavioural Therapy (CBT) for depression and to explore key factors that have impact on user experience and support engagement. Methods: We systematically identified apps described as being based on CBT for depression. We then conducted two studies. In the first, we analysed the therapeutic functionality of apps. This corroborated existing work on apps’ fidelity to CBT theory, but we also extended prior work by examining features designed to support user engagement. Engagement features found in CBT apps for depression were compared with those found in a larger group of apps that support mental well-being in a more general sense. Our second study involved a more detailed examination of user experience, through a thematic analysis of publicly available user reviews of CBT apps for depression. Results: We identified 31 apps that purport to be based on CBT for depression. Functionality analysis (Study 1) showed that they offered an eclectic mix of features, including many not based on CBT practice. CBT apps used less varied engagement features compared to 253 other mental well-being apps. The analysis of 1,287 user reviews of CBT apps for depression (Study 2) showed that apps are used in a wide range of contexts, both replacing and augmenting therapy, and allowing users to take active role in supporting their mental health and well-being. Users, including health professionals, valued and used apps that incorporated both core CBT and non-CBT elements, but concerns were also expressed regarding the unsupervised use of apps. Positivity was seen as important to engagement, e.g. in the context of automatic thoughts, users express a preference to capture not just negative, but also positive ones. Privacy, security and trust were crucial to the user experience. Conclusions: CBT apps for depression need to do a better job of incorporating evidence-based CBT elements. Equally, a positive user experience is dependent on other design factors, including consideration of varying contexts of use. App designers should be able to clearly identify the therapeutic basis of their apps, but they should also draw on evidence-based strategies to support a positive and engaging user experience. The most effective apps are likely to strike a balance between evidence-based CBT strategies and evidence-based design strategies, including the possibility of eclectic therapeutic techniques.