Trauma, coherence, and vigilance across scales: a fractal regulatory framework for public mental health and preparedness.

Public health systems increasingly operate under conditions of recurrent, overlapping crises, challenging their technical capacity and their ability to sustain coordinated vigilance and recovery. While individual trauma is extensively examined, its relevance to population mental health and civic preparedness is less frequently integrated across biological and institutional domains. This Perspective proposes a biologically informed, systems-oriented framework that conceptualizes trauma as a disruption of regulated coherence within complex adaptive systems. Drawing on nervous system regulation and health system resilience, the framework advances the organizing concept that core regulatory processes-differentiation, integration, and phase-sensitive coordination-recur across levels of organization. This cross-scale recurrence is an analytic analogy, not a claim of structural equivalence. Three propositions structure the argument: (1) trauma is a loss of regulated coherence rather than exposure alone, with recovery involving integrated regulation; (2) civic domains are specialized regulatory subsystems whose coordination under stress shapes collective stability or fragmentation; and (3) shared regulatory principles can support repair-oriented coordination over time without reliance on sustained centralized control. An illustrative vignette clarifies the operational logic of phase-sensitive coordination in an emergency. By reframing vigilance as a regulatory capacity-sustaining sensitivity to threat while preserving integration and repair-this framework offers a unifying conceptual lens for examining how institutional coherence influences public mental health outcomes during prolonged crises. Although conceptual, it highlights measurable domains for future empirical study, including coordination transitions, information flow, and repair processes, suggesting implications for preparedness planning and institutional design.