Abstract
Importance
Extreme risk protection orders (ERPOs) are state laws intended to prevent gun violence by preemptively and temporarily removing firearms from gun owners judged to be at risk of self-harm or violence against others. Evidence of their population-level impact on suicide remains limited and mixed.
Objective
To assess the association of California’s ERPO law with suicide risk among lawful handgun owners.
Design, Setting, and Participants
This cohort study used a difference-in-differences model, comparing suicide risk before (2012-2015) and after (2016-2021) implementation of California’s ERPO law among handgun owners and nonowners, assuming parallel trends and that the law had no impact on suicide among nonowners. Data were from the Longitudinal Study of Handgun Ownership and Transfer (LongSHOT), which includes more than 38 million registered voters in California with firearm transaction and mortality records. Statistical analyses were conducted from March to June 2026.
Exposure
Implementation of California’s ERPO law on January 1, 2016.
Main Outcomes and Measures
Death by all-cause suicide, firearm suicide, and nonfirearm suicide identified from mortality records using
International Statistical Classification of Diseases and Related Health Problems, Tenth Revision
, codes. Risk differences were expressed as 1-year suicide deaths per 100 000 persons.
Results
The analytic sample included approximately 172 million person-years (5 542 471 [nonunique] handgun owners and 166 624 345 [nonunique] nonowners aged 21 years or older). Handgun owners had a mean (SD) age of 44.4 (14.8) years in the prepolicy period and 47.2 (14.9) years in the postpolicy period. In both periods, most handgun owners were male (prepolicy period, 80.7%; and postpolicy period, 78.2%). Analyses showed a risk difference of −4.1 (95% CI, −9.5 to 1.3) suicide deaths per 100 000 persons in 1-year suicide risk among handgun owners following the implementation of the ERPO laws. Effect estimates were larger for firearm suicide (−3.0 [95% CI, −7.9 to 1.9]) compared with nonfirearm suicide (−1.1 [95% CI, −3.3 to 1.1]). Event study, subgroup, and negative control outcome analyses supported the main findings.
Conclusions and Relevance
This cohort study of California’s ERPO law and suicide risk among handgun owners estimated a modest population-level reduction in suicide risk, although a null effect cannot be ruled out, and such aggregate estimates do not necessarily imply ERPOs are ineffective among the individuals subjected to them. The findings reinforce the need for further research to understand the ways in which ERPOs can be used to reduce suicide.