Message Formats and Source Cues in Digital Mental Health Communication: Socioeconomic Differences in Engagement Intentions

Digital platforms are central to mental health communication, yet little is known about whether digital message characteristics shape engagement uniformly across socioeconomic groups. This research examines how the format and source characteristics of digital mental health messages influence information- and help-seeking intentions under stigma-sensitive conditions-and whether these effects are socially stratified. Two experiments with Korean young adults examined message format, emotional tone, corrective content, and speaker type. Study 1 compared two popular digital message formats-a narrative-message format and a short-form video format-paired with positive, negative, or neutral emotional framing. Among the two formats examined, participants exposed to the narrative-message format showed greater increases in both information- and help-seeking intentions than those exposed to the short-form video format, while emotional effects were conditional and varied across education-income intersections. Study 2 examined source cues by comparing AI and institutional speakers delivering corrective or non-corrective content. Corrective messages increased help-seeking intentions primarily when delivered by AI speakers, whereas institutional correction was more persuasive among higher-income participants. Across both studies, the observed message effects were systematically moderated by socioeconomic position. These findings suggest that digital mental health campaigns may reproduce or mitigate engagement inequalities depending on how different message formats and source characteristics align with audience resources and trust orientations.