This study has 3 objectives: to examine the association between state-level firearm ownership and suicide among adolescents of high school age; to compare the strength of the firearm ownershipÀsuicide association among adolescents relative to adults; and to evaluate the relationship between 11 child access prevention (CAP) laws and suicide. Method: Using an ecological time series cross-sectional design, we modeled suicide rates from January 1, 1991, to December 31, 2017, as a function of household firearm ownership and states' implementation of CAP provisions using fixed effect negative binomial models. Results: There were 37,652 suicides among adolescents between the ages of 14 and 18 years during the study period, and more than half of all suicides (51.5%, n ¼ 19,402) involved firearms. Each 10 percentage-point increase in states' firearm ownership was associated with a 39.3% (35.1%À43.5%) increase in firearm suicide, which in turn contributed a 6.8% (2.5%À11.1%) increase in all-cause suicide. The association between firearm ownership and suicide was approximately 2 times stronger among adolescents relative to adults. Policies mandating locks and safe storage were associated with a 13.1% (2.7%À22.3%) reduction in adolescent firearm suicide and an unexplained 8.7% (1.2%À15.7%) reduction in non-firearm suicide. CAP provisions were associated with reduced firearm suicide across the lifespan, but effects were stronger among adolescents.
Conclusion:There is an increased risk of adolescent suicide associated with household firearm ownership, and safe storage provisions are associated with decreased adolescent firearm suicide.