Stress Less by Design: Evaluating Usability and Stress Relief in a Self-Care App

As mobile self-care applications become increasingly common, understanding how their usability shapes emotional outcomes is essential. Prior research shows that self-care apps can reduce stress, but their effectiveness often depends on user engagement and adherence, which are strongly influenced by usability. Although poor usability is a frequent reason for disengagement, little is known about how users’ perceptions of usability relate to stress-reduction efficacy. The present study examined whether perceived usability predicted post-task distress, worry, and task engagement during a self-care exercise. Participants completed pre- and post-task stress measures and rated the app’s usability. While stress and worry decreased overall, usability showed a more complex pattern that contradicted hypotheses: higher usability predicted greater post-task distress, and this effect strengthened among participants with higher pre-task engagement. These findings highlight that effective self-care app design requires not just high usability, but usability that adapts to users’ engagement levels to maximize real-world therapeutic impact.