The current investigation explores the association between rates of household firearm ownership and suicide across the 50 states. Prior ecologic research on the relationship between firearm prevalence and suicide has been criticized for using problematic proxy-based, rather than survey-based, estimates of firearm prevalence and for failing to control for potential psychological risk factors for suicide. We address these two criticisms by using recently available state-level survey-based estimates of household firearm ownership, serious mental illness, and alcohol/illicit substance use and dependence.
Negative binomial regression was used to assess the relationship between household firearm ownership rates and rates of firearm, nonfirearm, and overall suicide for both sexes and for four age groups. Analyses controlled for rates of poverty, urbanization, unemployment, mental illness, and drug and alcohol dependence and abuse.
US residents of all ages and both sexes are more likely to die from suicide when they live in areas where more households contain firearms. A positive and significant association exists between levels of household firearm ownership and rates of firearm and overall suicide; rates of nonfirearm suicide were not associated with levels of household firearm ownership.
Household firearm ownership levels are strongly associated with higher rates of suicide, consistent with the hypothesis that the availability of lethal means increases the rate of completed suicide.