Every study that has examined the issue to date has found that within the U.S., access to firearms is associated with increased suicide risk.

Case Control Studies

Twelve or more U.S. case control studies have compared individuals who died by suicide with those who did not and found those dying by suicide were more likely to live in homes with guns.

For example, Brent and colleagues studied three groups of adolescents: 47 suicide decedents, 47 inpatient attempters, and 47 psychiatric inpatients who had never attempted suicide. Those who died by suicide were twice as likely to have a gun at home than either of the other two groups:

Adolescent Psychiatric Inpatients Adolescent Suicides Attempters Non-attempters Firearm in home 72% 37% 38%

A later psychological autopsy study (Brent 1999) compared 140 adolescent suicide decedents with 131 demographically similar community controls. Informants (usually a parent) for both groups were interviewed to learn about the adolescents’ life circumstances, mental health, and treatment status. Firearm access was a risk factor for suicide for both older (>15 years) and younger adolescents and for both males and females.

More studies (See “Firearm Availability and Suicide Prevalance: Case Control Studies” for studies covering male and female adults, blacks and whites, youths, elders, and other groups.)

How States Compare

Ecologic studies that compare states with high gun ownership levels to those with low gun ownership levels find that in the U.S., where there are more guns, there are more suicides. The higher suicide rates result from higher firearm suicides; the non-firearm suicide rate is about equal across states.

For example, one study (Miller 2007) used survey-based measures of state household firearm ownership (from the CDC’s Behavioral Risk Factor Surveillance System) while controlling for state-level measures of mental illness, drug and alcohol abuse, and other factors associated with suicide. The study found that males and females and people of all age groups were at higher risk for suicide if they lived in a state with high firearm prevalence. This is perhaps most concrete when looking not at rates or regression results but at raw numbers. The authors compared the 40 million people who live in the states with the lowest firearm prevalence (HI, MA, RI, NJ, CT, NY) to about the same number living in the states with the highest firearm prevalence (WY, SD, AK, WV, MT, AR, MS, ID, ND, AL, KY, WI, LA, TN, UT). Overall suicides were almost twice as high in the high-gun states, even though non-firearm suicides were about equal.

Suicides in the 15 U.S. States with the Highest vs. the 6 U.S. States with the Lowest Average Household Gun Ownership (2000-2002)

High-Gun States Low-Gun States Population 39 million 40 million Household Gun Ownership 47% 15% Firearm Suicide 9,749 2,606 Non-Firearm Suicide 5,060 5,446 Total Suicide 14,809 8,052

What is it about Guns?

Guns are more lethal than other suicide means. They’re quick. And they’re irreversible.

About 85% of attempts with a firearm are fatal: that’s a much higher case fatality rate than for nearly every other method. Many of the most widely used suicide attempt methods have case fatality rates below 5%. (See Case Fatality Ratio by Method of Self-Harm.)

Attempters who take pills or inhale car exhaust or use razors have some time to reconsider mid-attempt and summon help or be rescued. The method itself often fails, even in the absence of a rescue. Even many of those who use hanging can stop mid-attempt as about half of hanging suicides are partial-suspension (meaning the person can release the pressure if they change their mind) (Bennewith 2005).With a firearm, once the trigger is pulled, there’s no turning back.

Is it Rurality?

When two factors are associated, the relationship may be causal (one of the factors causes, or helps to cause, the other) or they may both be related to a third factor that plays a causal role. For example, suicide rates are higher in rural areas in the U.S. Firearm ownership is also higher in rural areas. Perhaps it is not the presence of firearms, per se, but something about rural life that leads to greater depression and suicidality, or, alternately, perhaps there is a character trait (such as self-reliance and an inclination to “go it alone”) that may be associated both with firearm ownership and suicide and it is this trait, not the presence of the gun, that leads to the association.

The evidence isn’t strong for either of these hypotheses. Most studies of rurality and depression (not all, but most) have found that people in rural areas do not have higher rates of depression than those in urban areas (e.g., Wang 2004). In addition, data from the National Comorbidity Study indicate that people living in homes with guns are about as likely as those living in homes without guns to suffer from depression, substance use problems, and suicidal thoughts (Ilgin 2008).

More studies – Rural-urban differences in depression and suicidality

Brent DA, Perper JA, Allman CJ, et al. The presence and accessibility of firearms in the homes of adolescent suicides: a case-control study. JAMA. 1991; 266:2989-2995.

Brent DA, Baugher M, Bridge J, Chen T, Chiappetta L. Age- and sex-related risk factors for adolescent suicide. Journal of the American Academy of Child and Adolescent Psychiatry. 1999; 38(12):1497-505.

Miller M, Lippmann SJ, Azrael D, Hemenway D. Household firearm ownership and rates of suicide across the 50 United States. J Trauma. 2007 Apr;62(4):1029-34.

Bennewith O, Gunnell D, Kapur N, et. al. Suicide by hanging. British Journal of Psychiatry. 2005;186:260-1.

Wang JL. Rural-urban differences in the prevalence of major depression and associated impairment. Social Psychiatry and Psychiatric Epidemiology. 2004 Jan;39(1):19-25.

Ilgen MA, Zivin K, McCammon RJ, Valenstein M. Mental illness, previous suicidality, and access to guns in the United States. Psychiatr Serv. 2008 Feb;59(2):198-200.