Abstract
BACKGROUND: Many people are affected by mental disorders. A transdiagnostic symptom and risk factor for most mental disorders is repetitive negative thinking (RNT). Psychotherapy can reduce RNT, but most people in need either do not receive psychotherapy or face long waiting times. In addition, people at risk for developing mental disorders do not receive psychotherapy. Mobile health (mHealth) interventions could overcome treatment barriers and support people at risk. OBJECTIVE: This scoping review aims to identify existing mHealth interventions for RNT and to give an overview of their characteristics regarding content, context, and technical features. Another aim is to identify which outcomes and questionnaires are used to measure RNT. METHODS: The scoping review will be conducted according to the JBI (Joanna Briggs Institute) methodology for scoping reviews and will be reported in accordance with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines. English-language, peer-reviewed literature involving mHealth interventions aimed at reducing RNT from 2003 onward will be included. A comprehensive search will be conducted in the following databases: PsycInfo, PubMed, Scopus, and Web of Science. Two independent reviewers will conduct a 2-stage blinded screening process (screening of title or abstract and full text) of the articles according to the inclusion criteria. A data extraction table will be used to extract information on the technology, content, delivery, accessibility, usability, feedback, and outcome measures of the interventions. Data charting, including coding and grouping, will follow an iterative process. The charted data will then be synthesized descriptively. RESULTS: Data collection began in February 2025 and is now complete, with 21 included articles meeting the inclusion criteria. As of December 2025, data charting is currently underway, and data synthesis will begin shortly. The final scoping review is expected to be submitted to a peer-reviewed journal by April 2026. CONCLUSIONS: The scoping review should lead to a better understanding of the conceptual possibilities and commonalities of current mHealth interventions for the transdiagnostic symptom RNT. It should provide starting points for systematic reviews and for the development of transdiagnostic mHealth interventions. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/72138.