Trust in the Digital Age: Mechanisms of Formation, Erosion, and Restoration in Health Information

Trust, defined as the willingness to accept vulnerability based on positive expectations of others’ intentions and actions, plays a critical role in health communication. Across health contexts, higher trust in institutional sources and official channels is associated with greater message believability, more accurate knowledge, and stronger adherence to recommended behaviors. This chapter conceptualizes trust in digital health communication as a multi-level and dynamic construct encompassing source or communicator trust (ability, benevolence, and integrity), information and message-design trust (perceived quality and clarity), and system or platform trust (privacy, security, transparency, and moderation fairness). Drawing on experimental, observational, and field research in vaccination, chronic disease management, screening, and public health crises, the chapter shows that trust often acts as a mediator between information exposure and health adherence. The chapter further examines the trust lifecycle, including its formation, erosion, maintenance, and repair. It highlights how heuristic processing, fast-scrolling environments, social identity cues, and platform affordances influence trust calibration. The erosion of trust is associated with inconsistent communication, lack of transparency, privacy violations, and inadequate management of uncertainty. In contrast, maintaining and restoring trust require prompt corrective actions, clear and transparent explanations, and appropriate accountability and remediation measures. Building on this synthesis, the chapter offers practical guidelines for health agencies, clinicians, platforms, journalists, and educators to operationalize trust-building strategies in digital environments. It concludes with a future research agenda focused on behavioural outcomes, longitudinal studies, equity-oriented methods, and the development of calibrated trust in AI-driven health communication. It positions trust as a core factor in effective and ethical public health interventions.