Subscribe
The latest psychology and neuroscience discoveries.
My Account
  • Mental Health
  • Social Psychology
  • Cognitive Science
  • Neuroscience
  • About
No Result
View All Result
PsyPost
PsyPost
No Result
View All Result
Home Exclusive Mental Health

Study finds mass shooters with suspected but undiagnosed mental health problems tend to have more victims

by Eric W. Dolan
July 29, 2019
in Mental Health
(Photo credit: fergregory)

(Photo credit: fergregory)

Share on TwitterShare on Facebook

A new study provides evidence that unaddressed mental health issues might increase violence in mass shootings. The findings have be published in the journal Psychology, Public Policy, and Law.

“I became interested in this topic for reasons probably similar to other researchers who have become interested in mass shootings. Initially, I was interested in why they occurred, but as I read more, I became more interested in how they differed,” said Logan A. Yelderman, an assistant professor of psychology at Prairie View A&M University and the corresponding author of the study.

“Much of the discussion about mass shootings surrounded how to prevent them, distinguishing between who is likely to become a shooter and who is not. I think that is the ultimate question people want answered, but I became more and more interested in how each mass shooting differed and what factors might have contributed to these variations.”

“I asked myself the simple question, ‘are the factors associated with variations in violence across shootings similar to those which predict them?’ I also wanted to know if certain policies might be helpful in addressing these factors. Thus, this research began.”

Yelderman and his colleagues analyzed 102 cases of mass shooters in the United States between 1982 and 2018. They found that most shooters obtained their guns legally (82.4%) and mental illness was reported to some extent in slightly over half of the cases (54.9%). About one-fourth of the mass shooters had spent time in a mental health facility or program. The average number of victims was 22.

The researchers found that mass shooters in which a mental disorder had been mentioned but no formal diagnosis was reported tended to have the most victims, compared to those with no reported mental health history and those who had received a formal diagnosis.

The Pulse nightclub shooter, for instance, was described as bipolar and mentally unstable by his wife, but had not been diagnosed with any specific condition. He killed 49 people and wounded 53 others.

“Our findings suggest that mass shooters with suspected mental health issues, yet who lacked formal diagnosis, tended to be more violent. This potentially implies that formal contact with mental health professionals or formal awareness of mental health might provide some buffering effect on violence among mass shooters. Also, shooters who had access to more weapons during the shooting tended to be more violent,” Yelderman told PsyPost.

Google News Preferences Add PsyPost to your preferred sources

“The main take-away (specific to policy) from our research is that policy discussions about mass shooting violence should not center on only guns or mental health but instead on gun ownership and responsibility and mental health. Two separate policies, one being a gun ban and the other being a mental health history restriction, are not the same as an integrative policy incorporating both mental health and gun control,” he added.

“Essentially, both mental health and firearm ownership/responsibility are key factors associated with mass shooting violence, and both need to be integrated in policy development and implementation. To focus on one and neglect the other would be unwise.

But the study — like all research — includes some limitations.

“There are three main caveats. First, our research addresses variations in violence among mass shooters; it does not address what leads people to become mass shooters,” Yelderman explained.

“Second, our data come from media and police reports; we did not have clinicians evaluate or validate diagnoses among the mass shooters, primarily because this proved problematic as most were deceased as the result of suicide or being shot by law enforcement. Nevertheless, we were unable to verify the reports independently.”

“Third, there are numerous ways to define a mass shooting, and we chose a definition that we thought represented the most accurate depiction of what current policy debates are actually about; however, it is possible that using other definitions might reveal different patterns in mass shooting violence.”

The study focused on seemingly random public shootings that resulted in more than three or four deaths. The researchers did not examine mass shootings related to gang activity and family slayings.

“Though policy is typically a good tool to improve the welfare of Americans, sometimes improvement requires change at the individual and community levels. Regarding mass shootings and other firearm violence, policy debates must include discussions about fundamental change in culture surrounding guns and mental health; otherwise, it is possible that policies will continue to risk failure,” Yelderman added.

“Developing policy to address gun violence should not be based on mass shootings alone, as they make up for a very small percentage of gun violence. Instead these policies should consider firearm violence of all kinds, including both mass shootings and non-mass shootings.”

The study, “Mass Shootings in the United States: Understanding the Importance of Mental Health and Firearm Considerations“, was authored by Logan A. Yelderman, Justin J. Joseph, Matthew P. West,and Erycha Butler.

Previous Post

Study finds threats to family predict women’s decisions to volunteer for a paramilitary organization

Next Post

Economic instability and household chaos are linked to physiological dysregulation in children

RELATED

Little-known psychedelic drug reduces motivation to take heroin in rats, study finds
Anxiety

Researchers find DMT provides longer-lasting antidepressant effects than S-ketamine in animal models

April 15, 2026
Midlife diets high in ultra-processed foods linked to cognitive complaints in later life
Mental Health

This Mediterranean‑style diet is linked to a slower loss of brain volume as we age

April 14, 2026
Legalized sports betting linked to a rise in violent crimes and property theft
Addiction

Ketone esters show promise as a new treatment for alcohol use disorder

April 14, 2026
Antidepressants may diminish psilocybin’s effects even after discontinuation
Depression

Psychedelic therapy and traditional antidepressants show similar results under open-label conditions

April 14, 2026
New study links honor cultures to higher rates of depression, suicidal thoughts
Addiction

Even mild opioid use disorder is linked to a significantly higher risk of suicide

April 13, 2026
Disrupted sleep is the primary pathway linking problematic social media use to reduced wellbeing
Mental Health

Disrupted sleep is the primary pathway linking problematic social media use to reduced wellbeing

April 13, 2026
Study finds microdosing LSD is not effective in reducing ADHD symptoms
Depression

Low doses of LSD alter emotional brain responses in people with mild depression

April 12, 2026
Extreme athletes just helped scientists unlock a deep evolutionary secret about human survival
Body Image and Body Dysmorphia

Can video games make kids feel better about their bodies?

April 12, 2026

STAY CONNECTED

RSS Psychology of Selling

  • The common advice to avoid high customer expectations may not be backed by evidence
  • Personality-matched persuasion works better, but mismatched messages can backfire
  • When happy customers and happy employees don’t add up: How investor signals have shifted in the social media age
  • Correcting fake news about brands does not backfire, five-study experiment finds
  • Should your marketing tell a story or state the facts? A massive meta-analysis has answers

LATEST

New psychology study links relationship insecurity to the pursuit of wealth and status

Republican lawmakers lead the trend of using insults to chase media attention instead of policy wins

Scientists wired up volunteers’ genitals and had them watch animals hump to test a long-held theory

New study sheds light on the mechanisms behind declining relationship satisfaction among new parents

A daily mindfulness habit can improve your memory for future plans

Sexualized dating profiles can sabotage long-term relationship prospects, study finds

Researchers find DMT provides longer-lasting antidepressant effects than S-ketamine in animal models

Online gaming might contribute to creativity, study finds

PsyPost is a psychology and neuroscience news website dedicated to reporting the latest research on human behavior, cognition, and society. (READ MORE...)

  • Mental Health
  • Neuroimaging
  • Personality Psychology
  • Social Psychology
  • Artificial Intelligence
  • Cognitive Science
  • Psychopharmacology
  • Contact us
  • Disclaimer
  • Privacy policy
  • Terms and conditions
  • Do not sell my personal information

(c) PsyPost Media Inc

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In

Add New Playlist

Subscribe
  • My Account
  • Cognitive Science Research
  • Mental Health Research
  • Social Psychology Research
  • Drug Research
  • Relationship Research
  • About PsyPost
  • Contact
  • Privacy Policy

(c) PsyPost Media Inc