Cultural Adaptation of a Digital Mobile App for Bipolar Disorder (PolarUs): Protocol for a Qualitative Co-design Study (Preprint)

BACKGROUND Bipolar disorder (BD) affects approximately 40 million people worldwide and is a chronic, potentially disabling mood disorder. Although effective treatments exist, access to evidence-informed psychosocial care remains limited, particularly for culturally and linguistically diverse populations, contributing to persistent global treatment gaps. Digital mental health interventions (DMHIs), such as smartphone apps, offer a promising means to improve access to self-management support and quality of life (QoL), an outcome prioritized by people with BD and in clinical guidelines. However, most apps for BD lack quality and are not culturally adapted or co-designed with people with BD, limiting relevance and engagement. PolarUs (mobile app) is an evidence-informed DMHI developed using co-design with people with BD. The app is structured on the core 14 domains from the QoL.BD scale, the only BD-tailored scale, combined with psychoeducation on self-management strategies and QoL. A recent pilot study demonstrated promising QoL, clinical, and feasibility outcomes. OBJECTIVE This study aims to culturally and linguistically adapt the PolarUs app into French, Chinese, and Spanish for the North American context using qualitative and co-design methods. METHODS Guided by community-based participatory research (CBPR) principles, whereby end users are engaged throughout the research process, and Bernal et al.’s Ecological Validity Framework, we will engage advisory groups of people with lived experience from each linguistic community throughout the cultural adaptation process. Semi-monthly virtual meetings will support systematic cultural adaptation of the self-management strategies, affirmations, and resources while maintaining fidelity to core evidence-based components. This will include cultural tailoring of app content and identification of culturally appropriate resources. Advisory groups will also contribute to co-interpretation of findings and co-design of culturally appropriate recruitment and implementation strategies of PolarUs for a future clinical trial. Meetings will be recorded and co-analyzed as research data with advisory groups using qualitative thematic analysis to capture advisory group perspectives and experiences. RESULTS This study was funded in October 2024. As of January 31, 2026, we enrolled 7 participants and results are expected to be published in fall 2026. CONCLUSIONS This study was funded in October 2024. As of January 31, 2026, we enrolled 7 participants and results are expected to be published in fall 2026.