Gun Violence and Mental Illness

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A December 2023 commentary in the American Journal of Medicine begins with this sobering sentence: "In 2021, the United States (US) experienced 47,286 deaths from gun violence, the highest ever.” The article goes on to quote Texas governor Greg Abbott’s assessment of this tragic loss of life from gun violence: “People want a quick solution. The long-term solution here is to address the mental health crisis.”

Is There a Relationship Between Gun Homicides and Mental Illness?

Once again, the high rates of gun violence in the U.S. are being blamed on mental illness. While mental illness is indeed a major factor for firearm-related suicides, some continue to advance the notion that it is also a factor for firearm-related homicides. To examine whether this is a plausible theory, the authors of the American Journal of Medicine piece compared the rates of gun homicides, gun ownership, and mental illness in the US to those in Australia and the United Kingdom (UK).

Here are the rates these authors report:

• Gun homicides: The US has a 10-fold higher rate of death from gun homicides than Australia and a 40-fold higher rate than the UK.
• Gun ownership: In the US there are 1.2 guns per person. In Australia there are 0.13 guns per person. In the UK there are almost no guns per person.
• Mental Illness: According to self-report, the rates of mental illness in 2019 were US 15.7%, Australia 17.6%, and UK 13.8%.

No Clear Relationship Between Gun Violence and Mental Illness

Note that the rates of mental illness are very similar among the three countries, so if mental illness were the cause of gun violence, the authors point out, we would expect the rates of gun violence to also be similar among the three countries, which of course they are not. From these data, the authors conclude that “The comparisons with Australia and UK indicate that mental illness is not the major contributor to the increasing trends in deaths from gun violence. In the US, the high rates of gun ownership and access to firearms and not mental illness seem more plausible explanations.”

This analysis, of course, is not without its limitations. As usual, we remind ourselves that associations are not the same as causation. We are comparing rates here and from them we cannot infer that those for gun ownership are the cause of gun homicides. Also, as the authors note, the mental illness rates are taken from self-reports rather than from a systematic objective assessment. Nonetheless, these rates accord fairly well with other, more rigorous data on rates of mental illness and do demonstrate that differences among the three countries are likely very small, much smaller than the differences in rates of gun homicides.

Unintentional Gun Deaths Among Children and Adolescents

Meanwhile, a report from the US Centers for Disease Control and Prevention (CDC), also from last December, tells us about another awful thing that is happening with all of those guns in the US: unintentional firearm deaths among children and adolescents. Most of those occur at home and involve guns that were stored unlocked and loaded. Approximately 4.6 million children in the US live in homes where guns are stored unlocked and loaded.

Why do we persist in trying to blame mental illness on gun violence in the US when study after study tells us that gun availability is much more likely to be the cause? We speculate that there are two main reasons. First, acknowledging that gun availability is more likely to be the proximate cause of firearm-related deaths would mean taking steps to limit gun ownership, something that is anathema to many citizens. Second, there is considerable misunderstanding about mental illness, with the pervasive and incorrect belief that people with mental illness are more likely than those without mental illness to be violent. In fact, studies show that people with mental illness are more likely to be the victims of violence than its perpetrators.

At very least, we need to be more aggressive about getting firearms stored in homes to be unloaded and locked. That would save the lives of children and adolescents who succumb to this source of violence, but is only a small fraction of the total number of gun deaths in the US. States that have the most restrictive gun laws also have the lowest rates of gun violence. That fact ought to mean something. The data here are clear: Gun violence is weakly related to mental illness and strongly related to rates of gun availability. While more must be done to address the worldwide mental health crisis, only more restrictive gun legislation will address the gun violence crisis.