1-2. Gun availability is a risk factor for suicide (literature reviews)

We performed reviews of the academic literature on the effects of gun availability on suicide rates.  The preponderance of current evidence indicates that gun availability is a risk factor for youth suicide in the United States.  The evidence that gun availability increases the suicide rates of adults is credible, but is currently less compelling.  Most of the disaggregate findings of particular studies (e.g. handguns are more of a risk factor than long guns, guns stored unlocked pose a greater risk than guns stored locked) are suggestive but not yet well established.

Miller, Matthew; Hemenway, David.  The relationship between firearms and suicide: A review of the literature.  Aggression and Violent Behavior: A Review Journal.  1999; 4:59-75.

Miller, Matthew; Hemenway, David.  Gun prevalence and the risk of suicide: A review.  Harvard Health Policy Review.  2001; 2:29-37.


3. Across states, more guns = more suicide (cross sectional analyses)

Using a validated proxy for firearm ownership rates, we analyzed the relationship between firearm availability and suicide across 50 states over a ten-year period (1988-1997).  After controlling for poverty and urbanization, for every age group, across the United States, people in states with many guns have elevated rates of suicide, particularly firearm suicide.

Miller, Matthew; Azrael, Deborah; Hemenway, David.  Household firearm ownership levels and suicide across U.S. regions and states, 1988-1997.  Epidemiology.  2002; 13:517-524.


4. Across states, more guns = more suicide (2) (cross sectional analyses)

Using survey data on rates of household gun ownership, we examined the association between gun availability and suicide across states, 1999-2001.  States with higher levels of household gun ownership had higher rates of firearm suicide and overall suicide.  This relationship held for both genders and all age groups.  It remained true after accounting for poverty, urbanization and unemployment.  There was no association between gun prevalence and non-firearm suicide.

Miller, Matthew; Lippmann, Steven; Azrael, Deborah; Hemenway, David.  Household firearm ownership and rates of suicide across U.S. states.  Journal of Trauma.  2007; 62:1029-35.


5. Across states, more guns = more suicides (time series analysis)

Using survey data on rates of household gun ownership, we examined the association between gun availability and suicide over time, 1981-2001.  Changes in the levels of household firearm gun ownership was significantly associated with changes in both firearm suicide and overall suicide, for men, women and children, even after controlling for region, unemployment, alcohol consumption and poverty.  There was no relationship between changes in gun ownership and changes in non-firearm suicide.

Miller, Matthew; Azrael, Deborah; Hepburn, Lisa; Hemenway, David; Lippman, Steven.  “The association between changes in household firearm ownership and rates of suicide in the United States, 1981-2002.”  Injury Prevention.  2006; 12:178-82.


6. Across states, more guns = more suicide (Northeast)

We analyzed data on suicide and suicide attempts for states in the Northeast.  Even after controlling for rates of attempted suicide, states with more guns had higher rates of suicide.

Miller, Matthew; Hemenway, David; Azrael, Deborah.  Firearms and suicide in the Northeast.  Journal of Trauma.  2004; 57:626-632.


7. Across U.S. regions, more guns = more suicide (cross sectional analysis)

We analyzed the relationship of gun availability and suicide among differing age groups across the 9 US regions. After controlling for divorce, education, unemployment, poverty and urbanization, the statistically significant relationship holds for 15 to 24 year-olds and 45 to 84 year-olds, but not for 25 to 44 year-olds.

Birckmayer, Johanna; Hemenway, David.  Suicide and gun prevalence: Are youth disproportionately affected?  Suicide and Life Threatening Behavior.  2001; 31:303-310.


8. Differences in mental health cannot explain the regional more guns = more suicide connection

We analyzed the relationship of gun availability and suicide among differing age groups across the 9 US regions.  Levels of gun ownership are highly correlated with suicide rates across all age groups, even after controlling for lifetime major depression and serious suicidal thoughts.

Hemenway, David; Miller, Matthew.  The association of rates of household handgun ownership, lifetime major depression and serious suicidal thoughts with rates of suicide across US census regions.  Injury Prevention.  2002; 8:313-16.


9. Gun owners do not have more mental health problems than non-owners

We added questions to, and analyzed data from the National Comorbidity Study.

Gun owning households do not have more mental health problems than non-gun owning households; differences in mental health do not explain why gun owners and their families are at higher risk for completed suicide than non-gun owning families.

Miller, Matthew; Molnar, Beth; Barber, Catherine; Hemenway, David; Azrael, Deborah.  Recent psychopathology, suicidal thoughts and suicide attempts in households with vs. without firearms: findings from the National Comorbidity Study Replication.  Injury Prevention.  2009; 15:183-87.


10. Gun owners are not more suicidal than non-owners

We analyzed data from the Second Injury Control and Risk Survey, a 2001-2003 representative telephone survey of U.S. households. Of over 9,000 respondents, 7% reported past-year suicidal thoughts, and 21% of these had a plan.  Respondents with firearms in the home were no more likely to report suicidal thoughts, plans or attempts, but if they had a suicidal plan, it was much more likely to involve firearms.  The higher rates of suicide among gun owners and their families cannot be explained by higher rates of suicidal behavior, but can be explained by easy access to a gun.

Betz, Marian E; Barber, Catherine; Miller, Matthew.  Suicidal behavior and firearm access: results from the second injury control and risk survey (ICARIS-2).  Suicide and Life Threatening Behaviors.  2011; 41:384-91.


11. Adolescents who commit suicide with a gun use the family gun

The vast majority of adolescent suicide guns come from parents or other family members.

Johnson, Rene M; Barber, Catherine; Azrael, Deborah; Clark, David E; Hemenway, David.  Who are the owners of firearms used in adolescent suicides?  Suicide and Life Threatening Behavior.  2010; 40:609-611.


12. The case-fatality rate for suicide attempts with guns is higher than other methods

Across the Northeast, case fatality rates ranged from over 90% for firearms to under 5% for drug overdoses, cutting and piercing (the most common methods of attempted suicide).  Hospital workers rarely see the type of suicide (firearm suicide) that is most likely to end in death.

Miller, Matthew; Azrael, Deborah; Hemenway, David.  The epidemiology of case fatality rates for suicide in the Northeast.  Annals of Emergency Medicine.  2004; 723-30.


13. The public does not understand the importance of method availability

Over 2,700 respondents to a national random-digit-dial telephone survey were asked to estimate how many of the more than 1,000 people who had jumped from the Golden Gate Bridge would have gone on to commit suicide some other way if an effective suicide barrier had been installed.  Over 1/3 of respondents estimated that none of the suicides could have been prevented.  Respondents most likely to believe that no one could have been saved were cigarette smokers and gun owners.

Miller, Matthew; Azrael, Deborah; Hemenway, David.  Belief in the inevitability of suicide: Results from a national survey.  Suicide and Life Threatening Behavior.  2006; 36:1-11.


14. Physicians need to do more to help reduce access to lethal means

This commentary presents the overwhelming evidence that the availability of lethal means increases the suicide rate and argues that physicians need to take an active role in reducing access for potentially suicidal individuals.

Miller, Matthew; Hemenway, David.  Guns and suicide in the United States.  The New England Journal of Medicine.  2008; 359:989-991.


15. Emergency department physicians and nurses rarely counsel about lethal means restriction

In one Boston emergency department (ED), ED physicians and nurses believe they should counsel suicidal patients on lethal means restriction, but they often don’t.  Psychiatrists working at the ED were much more likely to ask about firearms.

Betz, Marian E; Barber, Catherine; Miller, Matthew.  Lethal means restriction as suicide prevention: Variation in belief and practices among providers in an urban ED.  Injury Prevention.  2010; 16:278-81.


16. Emergency department physicians and nurses do not believe lethal means restriction can prevent suicide

Physicians and nurses at 8 emergency departments (n = 631) were surveyed about their practices and beliefs concerning means restriction and whether they asked their patients about guns. The proportion of providers who reported that they “almost always” ask suicidal patients about firearm access varied across five patient scenarios:  64% would ask a suicidal patient whose suicide plan involved firearms and 21% would ask a suicidal patient who did not have a specific plan.  Less than half believed that most suicides are preventable; two-thirds of nurses thought that most or all firearm suicide decedents would have died by another method if the firearm had not been available.

Many ED nurses and physicians do not understand the importance of the availability of lethal means in determining whether or not a suicide attempt ends in death.  The Means Matter Campaign needs to continue educating these professionals.

Betz, Marian E; Miller, Matthew; Barber, Catherine et al.  Lethal means restriction for suicide prevention: Beliefs and behaviors of emergency department providers.  Depression and Anxiety.  2013; 10:2013-20.


17. Mental health providers can be trained to reduce the risk of gun suicide

The Counseling on Access to Lethal Means (CALM) workshops were effective in improving mental health care providers’ attitudes, beliefs and skills regarding lethal means counseling.

Johnson, Rene M; Frank, Elaine; Ciocca, Mark; Barber, Catherine.  Training mental health providers to reduce at-risk patients’ access to lethal means of suicide: Evaluation of the CALM project.  Archives of Suicide Research.  2011 15(3): 259-264.


18. Suicide training in means reduction can be accomplished via the Internet

This article describes Harvard Injury Control Research Center’s (HICRC) National Center for Suicide Prevention Training, which uses the public health approach and includes training on means restriction.

Stone, Deborah; Barber, Catherine, Posner, Marc.  Improving public health practice in suicide prevention through online training: A case example. In: Sher, Leo & Vilens, Alexander, eds.  Internet and Suicide.  New York: Nova Science, 2009.


19. Lethal means reduction strategies can successfully reduce suicide

This article summarizes recent additions to the scientific literature about means restriction policies and suicide.

Johnson, Rene M; Coyne-Beasley, Tamera.  Lethal means reduction: What have we learned?  Current Opinion in Pediatrics.  2009; 21: 635–640.


20. Veterans have high rates of firearm suicide

There are no differences in suicide risk among middle-aged and older male veterans and non-veterans.  Suicide by firearm is higher, suicide by non-firearm is lower.  It is probable that lower baseline risk of active duty soldiers (healthy worker effect) tends to be counterbalanced by the accessibility of firearms to these veterans.

Miller, Matthew; Barber, Catherine; Azrael, Deborah, Calle, Eugenia E; Lawler, Elizabeth; Mukamal, Kenneth J.  Suicide among US veterans: A prospective study of 500,000 middle-aged and elderly men.  American Journal of Epidemiology.  2009; 170:494-500.


21. There are effective ways to reduce suicide without affecting mental health

This introduction to suicide as an international public health problem examines the role of promoting mental health, changing cultural norms, and reducing the availability of lethal means in preventing suicide.

Barber, Catherine; Miller, Matthew.  A public health approach to preventing suicide. In: Finkel, Madelon L.  Perspectives in Public Health: Challenges for the Future. Santa Barbara CA: Praeger Publishers, 2010.


22. Differences in suicide rates across the U.S. are best explained by gun prevalence

This summary of the scientific literature on suicide in the United States emphasizes the importance of levels of household firearm ownership in explaining different rates of suicide over time and across states, households and genders.

Miller, Matthew; Azrael, Deboarh; Barber, Catherine.  Suicide mortality in the United States: The importance of attending to method in understanding population-level disparities in the burden of suicide.  Annual Review of Public Health.  2012; 33:393-408.


23. Reducing access to lethal means can begin to reduce suicide rates today

This editorial in an issue of the flagship public health journal devoted entirely to veteran suicide emphasizes the importance of the availability of firearms in determining whether suicide attempts prove fatal.

Miller, Matthew.  Preventing suicide by preventing lethal injury: The need to act on what we already know.  American Journal of Public Health.  2012; 102(S1):e1-3.


24. The main factor explaining differences in suicide rates across states is gun ownership, not rates of suicide attempts

Using data from recently available state-level suicide attempt data, this study examines whether the association between state-level firearm ownership and completed suicide remains after accounting for suicide attempt rates.  Results show that firearm ownership rates – independent of underlying rates of suicidal behavior – largely explain the variation in suicide mortality across the 50 states.

Our results support the hypothesis that firearms in the home impose a suicide risk above and beyond baseline risk, and help explain why, year after year, several thousand more Americans die by suicide in states with higher than average household firearm ownership, compared with states with lower than average firearm ownership.  This study answers critics of the empirical literature who claim that the association between firearm ownership and suicide mortality reflects unmeasured suicidal proclivities associated with firearm ownership.

Miller, Matthew; Barber, Catherine; Azrael, Deborah; White R.  Firearms and suicide in the United States: Is risk independent of underlying suicidal behavior?  American Journal of Epidemiology.  2013; 178: 946-55.


25. U.S. cities with more guns have higher rates of suicide because of higher rates of gun suicide

Across metropolitan statistical areas that are comprised of large U.S. cities, higher rates of firearm ownership are strongly associated with higher rates of firearm suicide and overall suicide, but not with non-firearm suicide.  This study provides evidence consistent with previous case-control work and ecological studies across states and regions that firearms in the home increase the suicide risk.

We had previously shown that levels of household gun ownership largely explain the differences in suicide rates across regions and states.  This article shows that gun ownership levels also explain much of the differences in suicide rates across cities.  It is not altitude or remoteness from medical care facilities that can explain this gun-suicide connection.

Miller M, Warren M, Azrael D, Hemenway D.  Firearms and suicide in US cities.  Injury and Prevention.  2015: 21:e116-e119.


26. Firearms dealers can help prevent suicide

This article describes the New Hampshire gun shop project.  After a spate of firearm suicides, a committee of firearm dealers, firearm rights advocates, and suicide prevention professionals including HICRC worked on ways to help gun shops help prevent suicide.  Within a couple of years, half of New Hampshire gun shops were using suicide prevention materials developed by the committee.

The gun shop project has become a model of cooperation between public health professionals and gun advocates, a model that is being rolled out throughout the nation.  This is the first academic article describing the cooperation and documenting its success. HICRC personnel took the lead on the campaign’s written materials and the pre- and post-campaign interviews with gun shop owners.

Vriniotis M, Barber C, Frank E, Demicco R, and the NH Firearm Safety Coalition.  A suicide prevention campaign for firearm dealers in New Hampshire.  Suicide and Life-Threatening Behavior. 2015; 45(2): 157-163.


27. This article prioritizes the research needed to make a means restriction approach successful

This paper describes (a) the evidence about guns and suicide; (b) the types of voluntary programs (not command-and-control legislation) that will reduce firearm suicides, and (c) the research needed that can help create effective programs.

The National Action Alliance for Suicide Prevention and the National Institute of Mental Health (NIMH) asked HICRC to write priorities for firearm research.  This article describes a research agenda that will provide the knowledge to make a means restriction approach successful.

Barber C & Miller M. Reducing a suicidal person’s access to lethal means of suicide:  A research agenda.  American Journal of Preventive Medicine.  2014; 47(3):S264-72.


28. Guns, not antidepressant medication, explain the variants in suicide across the U.S.

This cross-sectional analysis of U.S. counties and states shows that differences in rates of suicide are not explained by differences in antidepressant medication, but are explained by levels of household firearm ownership.

Some mental health professionals have been claiming that antidepressant medication deserves the credit for the fall in suicide in the 1990s, and is the major reason some states have low suicide rates.  This article shows that it’s the guns.

Opoliner A, Azrael D, Barber C, Fitzmaurice G, Miller M.  Explaining geographic patterns of suicide in the U.S.: The role of firearms and antidepressants.  Injury Epidemiology.  2014; March 20, 1:6.


29. A summary for psychiatrists of the evidence on guns and suicide

This essay summarizes the evidence concerning guns and suicide for a leading psychiatry textbook on violence and mental illness.  It is part of our ongoing work to educate medical professionals to become knowledgeable about and advocates for the Means Matter approach to suicide prevention.

Miller M, Barber C, Azrael D.  Firearms and suicide in the U.S.  In: Gold LH, Simon RI eds.  Gun Violence and Mental Illness.  Arlington, VA: American Psychiatric Publishing.  2015.


30. A summary for sociologists of the evidence on guns and suicide

This essay, in the leading suicide textbook in the field, should help medical professionals to begin to use the Means Matter approach at the individual patient level and to promote it at the societal level.

Azrael D, Miller M.  Reducing access to lethal means: A review of the evidence base.  In: The International Handbook of Suicide and Attempted Suicide, 2nd ed.  West Sussex, England: John Wiley & Sons.  2015.  In press.


31. Guns alone explain the gun-suicide connection

This article demonstrates that it is virtually impossible for unmeasured confounding to explain the association between firearms and suicide.  The association is a real one.

Historically, the tobacco lobby claimed that the association between cigarettes and cancer could possibly be explained by some unknown risk factor for both.  This assertion was finally refuted when scientists showed the absurd degree of association between both that such an unmeasured confounder would have to have.  This article uses the same refutation for those who try to deny the causal association between guns and suicide.

Miller M, Swanson SA, Azrael D.  Are we missing something pertinent? A bias analysis of unmeasured confounding in the firearm-suicide literature.  Epidemiologic Reviews.  2016; 38(1):62-9.


32. Training increases whether providers ask about suicide

This study evaluated, via self-report, an intervention to change provider attitudes and practices related to suicide risk assessment at emergency departments (EDs).  The intervention trained clinicians in conducting universal risk assessment, but did not provide training on lethal means counseling. There was a substantial increase in the percentage of providers reporting universal screening and secondary assessment of suicide risk.  The proportion of nurses reporting often or almost always asking suicidal patients about firearm access increased (the proportion of doctors asking did not change).  Still, for both, the numbers asking remained low relative to ideal practice.

A gun in the home is a substantial risk factor for suicide.  Getting more providers to ask about firearms should help reduce completed suicides.  The findings supported the feasibility of implementing universal screening for suicide in EDs and points to the need for specific training in lethal means counseling.

Betz ME, Arias AA, Miller M, Barber C, et al.  Change in emergency department providers’ beliefs and practices after new protocols for suicidal patients.  Psychiatric Services.  2015; 66:625-31.


33. Patients appreciate counseling about firearms

Sixteen psychiatric emergency clinicians were trained via an online course written by HICRC to provide lethal means counseling with parents of patients under 18 years receiving care for suicidality.  Interviews with 114 families found that parents had favorable impressions of the counseling and good recall of the main messages.  Everyone who reported there were guns in the home at the time of the visit reported at follow-up that all were currently locked, compared to 67% reporting this at the time of the visit.

The project demonstrates the feasibility of a Means Matter intervention for families with at-risk children.

Runyan C, Becker A, Brandspigel S, Barber C, Trudeau A, Novins D.  Lethal means counseling for parents of youth seeking emergency care for suicidality.  Western Journal of Emergency Medicine.  2016; 17:8-14.


34. Many emergency department physicians fail to ask suicidal patients about firearms

In a study of eight emergency departments, half of patients treated for suicide ideation or attempts, who had firearms in the home, had not been assessed for access to lethal means.

This study demonstrates the importance of training in lethal means counseling since lethal means assessment in emergency departments is still not the norm.

Betz ME, Miller M, Barber C, Betty B, Miller I, Camargo CA, Bourdreaux ED.  Lethal means access and assessment among suicidal emergency department patients.  Depression and Anxiety.  2016; 33(6):502-11.


35. Ecological studies as well as case-control studies are important in understanding the connection of guns and violent death

The solicited commentary emphasizes the importance of the ecological studies of guns and suicide — that they overcame the “ecological fallacy”; the commentary also argues that ecological studies may be superior to case-control studies dealing with guns and homicide since men are usually shot outside the home with someone else’s gun.  The commentary shows that there is strong ecological evidence of the gun-suicide connection in addition to the solid evidence from the case-control studies.

This commentary was solicited by the journal editors and makes the case that the case-control studies analyzed in a recent meta-analysis provide only one part of the evidence that a gun in the home increases the risk of suicide.  Adding ecological (and other) studies makes the case overwhelming.

Hemenway D.  Guns, suicide, and homicide: Individual-level versus population-level studies (Commentary).  Annals of Internal Medicine.  2014 Feb; 160:134-135.