Mass Shootings and Mental Illness: A Teaching Moment?

"Looking for a piece of hay in a haystack"

  • by Staff Writer, MedPage Today

In the wake of last weekend's mass shootings in Dayton, Ohio and El Paso, Texas, President Donald Trump cited "mentally ill monsters," as a source of violence in a press briefing Monday.

"We must reform our mental health laws to better identify mentally disturbed individuals who may commit acts of violence and make sure those people not only get treatment but, when necessary, involuntary confinement," he said at the briefing.

"Mental illness and hatred pulls the trigger," he continued. "Not the gun."

But psychiatric specialists rejected this claim.

"It is important to note that the overwhelming majority of people with mental illness are not violent and are far more likely to be victims of violent crime than perpetrators of violence," the American Psychiatric Association responded. "Rhetoric that argues otherwise will further stigmatize and interfere with people accessing needed treatment."

Patients with psychiatric disorders actually account for a quarter of crime victims in any given year. And although mental illness has been shown to play a role in more mass shootings than other forms of large-scale homicides, the attributable risk of violence remains low, at just 4%.

So why is mental illness so likely to make headlines following a mass shooting?

It may be a means of grasping an intangible idea -- a way for the public to understand a senseless act, said psychiatrist Amy Barnhorst, MD, of the University of California Davis.

"It's hard for people to understand why they would have done it and they want to come up with some explanation," Barnhorst told MedPage Today. "Many people don't really understand what mental illness is, they just think it's a problem with your mind. They think [a shooter's] mind must not be working, and that's why this happened."

Joe Parks, MD, of the National Council for Behavioral Health (NCBH) in Washington, D.C., said it may be a matter of language. The distinction between mental illnesses like schizophrenia and other mood disorders has been elastic in this context, he said, often stretched by various groups to fit their agendas.

"If the definition is narrow, including only persons with a severe mental disorder characterized by psychotic symptoms, then only a small proportion of mass shootings are committed by a person with mental illness," he told MedPage Today in an email.

"But under a broad definition, persons with mild depression, adjustment problems, substance abuse, or personality disorders would be counted," he continued. "And then nearly all of the mass shootings are committed by persons with mental illness."

Casting the blame on mental illness may also be a means of distraction, diverting attention from discussions about access to firearms, said mental health specialist Emma Beth McGinty, PhD, of John Hopkins Bloomberg School of Public Health in Baltimore.

On one hand, it may seem like improving underfunded mental health systems as Trump recommended is a step in the right direction. But on the other hand, doing so will probably not reduce violence considering the small proportion of mentally ill individuals who commit violent acts, McGinty said.

"The evidence also clearly suggests that, even in cases where symptoms of mental illness do play a role in a perpetrator's actions, it is never or almost never only the mental illness that contributed to that action," McGinty told MedPage Today.

Factors like antisocial personality traits or other behavioral patterns are more closely tied to criminal recidivism than mental illness, according to an NCBH report released Tuesday.

Specifically, most prior shooters have experienced childhood trauma and had a crisis in the weeks predating the shootings, according to The Violence Project, an ongoing database cataloguing more than 100 mass shootings over the past 20 years. Bullying victimhood is often cited as a feature of many shooters' pasts.

The majority of mass shooters in the project did have some evidence of mental illness, such as a formal diagnosis or histories of psychiatric medication, said project co-founder Jillian Peterson, PhD, of Hamline University in St. Paul, Minnesota. However, it has been estimated that half of U.S. adults will develop at least one mental illness in their lifetime.

So isolating one of these factors -- like mental illness -- and pinning it as the reason for an attack does not tell the full story.

"Blaming mental illness is the same as blaming men," Peterson told MedPage Today. "Yes, that is a factor, but it's so much more complex than that."

Histories of violence or criminal charges are also common among shooters. In an analysis of 28 public attacks in 2017, 20 were carried out by someone with a criminal history or domestic charges; 18 involved a perpetrator who had previously committed acts of violence or been treated for mental health symptoms.

All 28 attacks seemed to be precipitated by a recent stressor such as financial instability or troubled relationships. Nearly all aggressors were male, and most were white.

In the context of mass shootings, perpetrators also tend to turn outwards to have their ideas reinforced or radicalized, which can be accomplished through social media, Peterson said. They may also research prior shootings, Peterson added.

Trump also cautioned against the "perils of social media and the internet." However, he also promised to use social media as a tool for detecting mass shooters "before they strike."

Still, profiling potential threats on the basis of commonalities that past shooters share casts the net too far, the NCBH report warned, resulting in high rates of both false negative and false positive identifications. And Peterson cautioned that involuntary confinement can exacerbate feelings of isolation and injustice for some individuals at risk for violence -- and such confinement is typically short.

Last February, Barnhorst wrote in the New York Times about a case she had seen in which involuntary confinement may have prevented a mass shooting. Police sent her a teenager found with a kill list in his locker, plans to purchase a handgun posted on the dark web, and Instagram posts suggesting a desire to turn his school into "Columbine 2.o."

She and local authorities "turned to a rarely used statute in California" that allows individuals to remain confined for up to 6 months, which let them monitor and treat the teen. After his release, he earned his high school diploma, and now lives in a group home. For the first time in his life, he wasn't living as an outcast, Barnhorst said.

But this was the exception, she emphasized. It was the threats of violence that alerted authorities, not any signs of "mental illness." Normally, she told MedPage Today, identifying mass shooters before they act is like "looking for a piece of hay in a haystack."


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