Socio-Spatial Patterns of Suicide Mortality in the United States

TL;DR

This study investigates how social networks and firearm restriction policies influence suicide mortality rates across US counties, revealing significant effects of social ties and protective policies on suicide risk.

Contribution

It introduces an integrated analysis of social connectedness and firearm policies, demonstrating their roles in the spatial diffusion of suicide risk and prevention.

Findings

Higher social connectedness correlates with increased suicide mortality.

Firearm restriction policies are associated with reduced suicide deaths.

Social networks influence both harmful exposures and protective interventions.

Abstract

Suicides cause over 49000 deaths yearly in the United States, 55% involving firearms. Suicide mortality exhibits substantial geographical and sociodemographic heterogeneity; yet the role of social networks remains underexplored. To assess how suicide risk and firearm restriction policies propagate through social ties, we integrate county-level suicide mortality data (2010-2022) with the Facebook Social Connectedness Index (SCI). We also examine Extreme Risk Protection Orders (ERPO), state-level policies restricting firearm access for individuals at risk of self-harm. In two-way fixed effects regressions, a one-standard-deviation increase in the SCI-weighted average suicide mortality rate of connected counties was associated with +2.78 deaths per 100,000 in a focal county, while a one-standard-deviation increase in ERPO social exposure was associated with -0.214 deaths per 100,000. These associations persisted when adjusting for geographic proximity and including state-by-year fixed effects, and confirm the effect of social networks on diffusion of both harmful exposures and protective interventions.