Help on Demand: Development of a Self-Directed Mobile App Intervention for Gambling Problems

Abstract

Not all individuals with gambling problems need or seek intensive professional treatment. The demonstrated reach and effectiveness of less intensive self-directed interventions make them a natural focus for innovation. However, their impact is often constrained by low user engagement. Previous efforts to increase engagement have often added brief clinician contact, which compromises core advantages of self-directed interventions, such as privacy, autonomy, and scalability. An alternative approach is to modify intervention design features to enhance usability and appeal, such as through personalization and tailoring. The overarching aim of this dissertation was to develop and evaluate a personalized self- directed mobile app intervention for gambling problems, following a streamlined version of the ORBIT model for behavioural intervention development. Phase I involved a scoping review of user engagement with technology-mediated self-guided interventions (TMSGIs) for addictive disorders, drawing on conceptual and treatment parallels between gambling disorder and substance use disorders. The review summarized intervention features (e.g., structure, tailoring), identified heterogeneity in engagement measurement, trajectories, and effects, and synthesized factors that facilitate or hinder user engagement. Phase II focused on intervention development and initial feasibility testing with a small sample of individuals with past or present gambling problems. These early findings informed subsequent modifications and testing. Phase III reported preliminary results from the first randomized controlled trial comparing the personalized app developed in Phase II against a static version modelled after conventional self- help workbooks. Outcomes related to engagement, gambling behaviour, and concurrent mental health were presented and discussed. Taken together, this dissertation advances understanding of how personalization, engagement, and structure interact within self-directed digital interventions for gambling problems. It underscores that the effectiveness of these interventions hinges not only on content but also on design features that align with user motivations and habits. Continued methodological innovation, conceptual precision, and ethical vigilance will be essential for realizing the potential of scalable, equitable, and effective digital care for people experiencing gambling-related harm.