This article references potential trauma triggers, including gun violence, mass shootings, hate crimes, and suicide. If you are in distress and need immediate help, please find a crisis hotline in your country here.
So far in 2022, more than 500 deaths from mass shootings have occurred in the US.¹ Using the Gun Violence Archive’s definition, a mass shooting is any incident with a minimum of four victims shot (either injured or killed).
In 2020, the Centers for Disease Control and Prevention (CDC) released data showing that the leading cause of death among children ages 1–18 is a firearm.² ³
Earlier this year, US Senator Charles Schumer lamented, "America doesn’t stand out when it comes to the rate of mental illness, but we are unique among the world’s developed nations in that today, the leading cause of death among children is no longer a car accident, is no longer illness or malnourishment."⁴
A particularly high-profile mass shooting occurred earlier this year in Uvalde, Texas, at an elementary school where 18-year-old Salvador Ramos shot 19 schoolchildren and two teachers.⁵
Less than two weeks before that tragedy, Payton Gendron was accused of targeting, shooting, and killing 10 Black people in a supermarket in Buffalo, New York.⁶
The proceedings are ongoing, and Gendron is indicted for hate crimes and weapons offenses. He also faces domestic terrorism charges.⁷
In 2021, the Federal Bureau of Investigation (FBI) recorded 61 active shooter incidents in the US — a 96.8% increase since 2017.⁸
The FBI defines an active shooter incident as "one or more individuals actively engaged in killing or attempting to kill people in a populated area."
It can be difficult to comprehend what leads people to such extreme, aberrent behavior. In the search for an explanation, many, including politicians and the media, highlight mental illness as a primary reason a person would commit horrific crimes.
However, there is much to know about the extent to which mental illness is (and isn’t) a risk factor for gun violence.
Enduring, harmful myths and stereotypes about mental illness and violent tendencies deserve to be dismantled.
Surveys show that quite a few people hold a mistaken belief that those with severe mental illness are highly likely to be violent. Some experts call this belief tendency a “deranged shooter” narrative.⁹
Earlier this year, US president Joe Biden gave remarks in which he emphasized the need to "address the mental health crisis deepening the trauma of gun violence and as a consequence of that violence.”¹⁰
He has been criticized for connecting mental health to gun violence at other times as well.¹¹
Former US president Donald Trump also mentioned that mental health issues must be addressed to reduce mass shootings.
While condemning acts of mass violence, Trump once asserted that “mental illness and hatred pull the trigger, not the gun.”¹²
Unfortunately, comments of this nature can perpetuate the idea that guns aren't the central problem (and that violence occurs when guns are put in the hands of people with mental health disorders).
Just recently, Biden signed the most significant US gun safety legislation passed in decades, the Bipartisan Safer Communities Act.¹³
These new laws invest in children and family health services, community violence-prevention initiatives, and an enhanced review process for firearm buyers under 21.
However, a partisan gap regarding Biden’s pledge to ban assault weapons continues.¹⁴ ¹⁵
Unfortunately, popular media also seems to fuel peoples’ perception that individuals with mental illness are inherently dangerous.
In 2013, a US national public opinion survey with 1,530 participants found that just over 46% agreed that those with serious mental illness are “far more dangerous than the general population.”¹⁶
A 2015 news poll conducted with 1,000 Americans found that 63% of respondents believe that mass shootings reflect issues in identifying and treating those with mental illness.¹⁷
Only 23% of the same group surveyed attributed mass shooting violence to inadequate gun control laws.
In a 2017 poll, The American Psychiatric Association found that 70% of respondents believed lack of access to mental health services contributes to mass shooting violence.¹⁸
Whether news outlets link mental illness to violence due to poor research or to sensationalize stories, there is little evidence to support such claims.
A 2016 analysis published in the Health Affairs journal examined a random sample of 400 news articles about mental illness published between 1995–2014.¹⁹
Researchers found that more than half of these stories linked people with mental illness with violent behavior.
A mere 14% were about recovery or positive treatment outcomes.
A systematic review of nine studies found that a person with severe mental illness is between 2.3–140.4 times at greater risk of being the victim of violence than the general population.²⁰
Experts cite several reasons for this heightened risk.
First, being mentally ill might impair a person’s ability to assess a situation for what it is rather than how they wish it to be or fear it. In clinical terms, this is known as "reality testing." For instance, believing a negative, irrational thought about oneself is an example of impaired reality testing.
Mental illness is also associated with impairments in insight and judgment.
Insight is a person’s ability to be aware of themselves, such as awareness of one’s mental health issues and the limitations caused by mental health concerns.
Judgment is a person’s ability to avoid actions and decisions that could be harmful to themselves or those around them.
Essentially, having trouble distinguishing what's happening in your mind versus the outside world, poor self-awareness, and difficulty assessing danger can make it challenging to identify potential threats.
Also, many mental illnesses cause disorganized thought processes, making it difficult to evaluate and respond effectively to potential danger.²⁰
This is not to suggest that mental illness doesn't factor into mass violence at all.
But there are significant issues with how the public correlates severe mental illness and mass shootings.
First, mental illness encompasses many diagnoses with vastly different symptoms.
When surveyed, people seem likely to connect mass violence with disorders on the psychosis spectrum — which often involve symptoms like seeing or hearing things (i.e., hallucinations).
For example, having delusions, unusual beliefs, and hallucinations are symptoms of schizophrenia.
However, according to Columbia University’s expert Ragy Girgis, MD, MS, associate professor of clinical psychiatry, only about 5% of mass shootings correlate with severe mental illnesses like schizophrenia or another psychotic disorder.²¹
Around 25% of mass shooters do have non-psychotic forms of mental illness, such as depression.²¹
In a recent Psychology Today article, Amy Barnhorst, MD, made an important distinction pointing out that hate is not a clinically recognized form of mental illness:
"Most of the time, mass shooters aren’t driven by delusions or voices in their head. They are driven by a need to wield their power over another group. They are angry at the perceived injustices that have befallen them at the hands of others — women who wouldn’t sleep with them, fellow students who didn’t appreciate their talents, and minorities enjoying rights that were once only the privilege of white men like them. It's not an altered perception of reality that drives them — it's entitlement, insecurity, and hatred. Maybe some of them also have depression, ADHD, or anxiety, but that is not why they opened fire on a group of strangers,” explains Barnhorst.²²
Although hate isn’t an official mental illness in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5), hateful attitudes and actions are associated with some personality disorders, notably antisocial personality disorder (ASPD).
(In contrast, hate and hate-related behaviors aren’t symptoms of depression, anxiety, bipolar disorder, schizophrenia, or other disorders that might come to mind when you think of mental illness).
Individuals with ASPD show symptoms that fit with hate or hate-related behaviors. It is these behaviors that often put these individuals at risk of harming others and being incarcerated.²³ Traits associated with ASPD usually include:
Lack of empathy and reckless disregard for others
Not having a clear sense of the “right thing to do” (conscience)
Willingness to deceive or con others for personal benefit
Verbal and/or physical aggression, and unlawful behavior
Spitefulness, vindictiveness, or revenge-seeking against one or more people/groups
Impulsive actions that are harmful and abusive to others
Intense desire to cause harm, including severe physical or emotional injury, or death
Still, there isn’t a standard effective treatment for this extremely complex personality disorder, and experts say it remains extremely difficult to predict an individual's long-term risk of violence.²³ ²⁴
In an interview with Dartmouth Medicine, assistant professor of psychiatry Benjamin Nordstrom explained, “When people are hospitalized, we can predict pretty accurately the short-term risk of small-scale violence, such as shoving a nurse. But we're not capable of predicting with any accuracy whether a person is likely to carry out a mass shooting, or really any other kind of violence out in the community.”²⁴
Poor anger control and impulsivity are symptoms present in other mental illnesses. However, this does not necessarily indicate that displaying poor anger control and impulsivity means a person has an antisocial personality disorder.
Disorders such as attention-deficit/hyperactivity Disorder (ADHD), post-traumatic stress disorder (PTSD), bipolar disorder, and major depressive disorder (MDD) are all mental illnesses whereby affected individuals can struggle with anger issues and impulsivity.
The central difference is that someone with ASPD may avoid taking responsibility for their actions or even blame their victim(s) for provoking them.²³
In contrast, someone affected by PTSD might have an angry outburst and even injure someone, but afterward, there is usually a feeling of remorse.
A person with bipolar disorder, for instance, may become aggressive, but aggression is more likely to occur during manic episodes that are typical of this mental illness.
In between manic episodes, the person’s mood will be more stable, so aggressive outbursts are less likely to occur. With ASPD, there are no “episodes” of heightened symptoms because symptoms are a part of the individual’s personality.
Mass shootings account for less than 0.5% of all homicides in the US.²⁵
If we look more broadly at any form of firearm violence, experts have found that only 1% of firearm deaths are related to severe mental illness.²⁶
Even when researchers widen the criteria to any form of interpersonal violence, they get similar results.
For example, suppose we could eliminate mental illness as a violence risk factor. Some scientists suggest that violent acts toward others would fall by less than 4%.²⁶
The US also has the highest firearm homicide rate and more mass shooting incidents than other high-income nations with similar rates of mental illness.
It's estimated that deaths from gun violence are almost 25x higher in the US than in other developed nations. Yet, we don't hear people saying that being American is a risk factor for developing mass shooting behavior.²⁷ ²⁸
Evidence suggests that some mental illnesses and disordered behaviors do raise the risk of violence, including:
By some estimates, as many as 75% of those seeking help for substance use disorder (dependency on alcohol and drugs) have committed interpersonal violence.²⁶
Another study³⁰ has shown that those with diagnosed drug use disorder are 4 –10x more likely to be violent than the general population.²⁹
An estimated 23% of mass shootings are linked to substance use, but experts say that addiction was still not the primary cause of their violent behavior.²⁰
In studies, mental illnesses that have a stronger correlation with violence tend to include antisocial or narcissistic personality disorders (sometimes in combination).³⁰
ASPD is characterized by a lack of empathy, impulsivity, and a disregard for social norms and rules. Individuals with this disorder often have manipulative and deceitful traits.
It's estimated that 85% of people with ASPD have acted violently toward others. According to one study, 50% of incarcerated people meet the criteria for diagnosable ASPD.³¹
The correlation between ASPD and mass shootings is understudied.
Current evidence suggests that many mass shooters may have antisocial traits but not clinically diagnosable personality disorders.³¹ ³²
Narcissists are egocentric and have a grandiose sense of self-importance. They require excessive admiration and are often preoccupied with power and success.
Several experts have suggested that many mass shooters are aggrieved narcissists reacting to perceived humiliation.³³ ³⁴ ³⁵
A 2009 meta-analysis found that 9.9% of people with schizophrenia studied had been violent at any time — a rate 5x higher than the general population.³⁶
Homicide risk was also higher in those with schizophrenia — 0.3% compared to 0.02% in the broader population.³⁶
However, experts emphasize that violent crimes perpetrated by individuals with schizophrenia still only constitute a small fraction (less than 10%) of overall violence in the population.³⁷
Considering all this evidence, it seems that public discourse overweighs mental illness as a risk factor for violence.³⁸
Although some forms of mental illness can contribute to the profile of a mass shooter, it does not mean that diagnosed mental illness is a leading cause of mass shootings.
Using similar reasoning, you would need to examine being male as a risk factor. The male-to-female ratio of mass shooters is 24:1.³⁹
Associate professor of clinical psychiatry, Ragy Girgis, MD, told Columbia Psychiatry News, "Half of all mass shootings are associated with no red flags — no diagnosed mental illness, no substance use, no history of criminality, nothing. They are generally committed by middle-aged men who are responding to a severe and acute stressor, so they're not planned, which makes them very difficult to prevent."²¹
So, while addressing mental illness should always be a public health priority (especially because 1 in 5 Americans live with some form of mental illness), this alone isn’t a sound strategy for reducing or preventing mass shootings.⁴⁰
To date, one of the best explanations of why mass shootings happen comes not from the field of psychiatry, but from criminal justice.
For two years, associate professor Jillian Peterson from Hamline University; and James Densley, professor of Criminal Justice and Department Chair of the School of Law Enforcement and Criminal Justice at Metro State University, compiled data about all mass shootings in the US since 1966.
Their research involved speaking to the perpetrators, their families, survivors of the shootings, and first responders.⁴¹
Peterson and Densley also reviewed media coverage and criminal case details (like suicide notes, trial transcripts, and medical records).
Their findings revealed four things mass shooters have in common:
Trauma Most mass shooters experienced early childhood trauma of some kind and were exposed to violence from a young age. The trauma frequently led to some form of mental health issue, including depression, anxiety, or psychosis.
Major life crisis All mass shooters in this research had a distinct crisis occur in the weeks or months before the shooting. For example, being fired from a job or facing rejection within a relationship.
Fixation with other notorious shootings Most mass shooters studied other shooters before committing their own acts of violence and sought validation for their motives. As one shooting receives notoriety, it encourages other potential shooters. Many also looked for validation online to justify their intention to murder. In this way, mass shootings can be socially contagious, which is why we often see them happening in clusters.
Resources All mass shooters had the resources to carry out their plans. Peterson and Densley’s research found that 80% of perpetrators who chose a school setting as the site of their crime got their firearms from a family member.
Based on the above mass shooter profile developed by Professors Peterson and Densley, they have suggested tactics for preventing future mass shootings:
Reducing resources makes it harder for a potential mass shooter to complete their plan. Controlling access to guns and weapons by making them more difficult to obtain through age restrictions and universal background checks is key. Increased security in high-risk areas is another possible measure.
Stopping the release of perpetrators' personal information could be an effective way to stop the fame and attention they seek. It could also reduce copycats.
Employers, teachers, and other community leaders should be encouraged to start conversations about mental health. Systems also need to be in place to identify a person in crisis — particularly a person who is in crisis and showing anger — and direct them to the best services for help.
Oftentimes, mass shooters spoke to someone about their thoughts or plan to harm others. In some cases, these sentiments are posted online by the mass shooter before the violent act.
The urgency behind reducing mental illness stigma
Unfortunately, disproportionately linking mental illness of any kind or severity with gun violence and mass shootings only adds to the existing stigma of living with a mental health disorder.
Facing stereotypes and discrimination about mental illness can have a profound impact on the affected person’s quality of life. It can be a barrier to seeking employment, housing, a sense of belonging within one’s community, relationships, and more.⁴² ⁴³
Those who live with mental illness often contend with being thought weak or incapable of directing their own life. Adding the stereotype of being inclined to violence can make it harder to seek treatment and have an isolating effect.
In addition, external stigma from society can then become internalized as self-stigma — when an individual starts to believe the negative messages and beliefs imposed by society.
A 2017 study found that self-stigma is linked to poorer health outcomes for those with mental illness.⁴⁴
While it might seem like putting a spotlight on mental health is a positive step toward directing more resources and funding to this healthcare area, casting gun violence as mainly a mental health issue is problematic.
Doing so risks further marginalizing an already-marginalized group and can distract from the issue of advancing meaningful changes to gun-control legislation.
Improved mental health support and resources are a crucial need for society, and more resources should be directed to this area. However, we cannot expect this to be a cure-all for the current rise in mass shootings.
Instead, it’s necessary to use a comprehensive approach. Reducing gun violence necessitates stricter gun control laws, better background checks, and reducing the publicity that mass shooters seek.
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Mass shootings in 2022 | Gun Violence Archive
WISQARS fatal injury data visualization | Centers for Disease Control and Prevention (CDC)
Fact-check: Are firearms the leading cause of death in children? | Austin American-Stateman
“Systemic failures” in Uvalde shooting went far beyond local police, Texas House report details | The Texas Tribune (2022)
Family members of buffalo mass shooting want focus on preventing racial violence, not death penalty | Death Penalty Information Center
Remarks by President Biden on gun violence in America | The White House
Texas GOP to biden: 'Come and take it' on assault weapons ban pledge | The Center Square
What Americans blame most for mass shootings (hint: it’s not gun laws) | The Washington Post
Americans overwhelmingly see gun violence as a public health issue; they want congress to act and CDC to conduct research | American Psychiatric Association
Is there a link between mental health and mass shootings? | Columbia University Department of Psychiatry
Hate is not a mental illness | Psychology Today
Can acts of violence be prevented or predicted? | Darmount Medicine
Mental illness and gun violence | Educational Fund to Stop Gun Violence
How drugs & alcohol can fuel violent behaviors | American Addiction Center
Personality disorders and propensity to violence? | Violence Lab
Literature review of mass shooter motivations | Malmo University
Part B: What we heard - 7. Stereotypes about people with mental health or addiction disabilities | Ontario Human Rights Commission
Stigma, prejudice and discrimination against people with mental illness | American Psychiatric Association
Dawn Teh is a health writer and former psychologist who enjoys exploring topics about the mind, body, and understanding what helps humans thrive.