Co-developing tools to support student mental health and substance use: Minder app development from conceptualization to realization

University students experience a high prevalence of mental health and substance use concerns; however, few students access support for these challenges. Although digital mental health interventions have been promoted as a means of addressing this need, engagement with these tools is often poor. A lack of user-centric design is frequently cited as a reason for low engagement. The goal of this study is to describe the co-development processes and associated feedback used to develop the Minder app, a tool designed to support a non-clinical population of university students to maintain mental wellbeing and manage substance use. This process can be organized into three main phases: conceptualization and initial app design, iterative user testing, and final app design. As a result of meaningful engagement with end-users throughout the design and testing process, key changes were made to the design (e.g., graphical interface), content (e.g., language used, addition of components related to general wellbeing), and support (e.g., peer coaching) provided within the app. In addition to describing these changes, we also discuss considerations related to the broader implementation and scale-up of the Minder app within existing university systems.