PsyPost
  • Mental Health
  • Social Psychology
  • Cognitive Science
  • Neuroscience
  • About
No Result
View All Result
Join
My Account
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
Reading Time: 3 mins read
(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.

RELATED

Misophonia is strongly linked to a higher risk of mental health and auditory disorders
Mental Health

Lavender tea routine linked to reduced emotional distress in misophonia sufferers

June 1, 2026
The tendency to feel like a perpetual victim is strongly tied to vulnerable narcissism
Alzheimer's Disease

Artificial intelligence sheds light on how some brains resist Alzheimer’s memory loss

June 1, 2026
Brain scans identify the neural network that traps anxious people in cycles of self-blame
ADHD Research News

Irregular brain maturation in childhood predicts emotional habits in early adolescence

May 31, 2026
New research sheds light on cannabinoids’ impact on anxiety during alcohol withdrawal
Addiction

Lesser-known cannabis compounds show promise for treating alcohol addiction in rats

May 31, 2026
Data from 560,000 students reveals a disturbing mental health shift after 2016
Anxiety

Undigested fructose linked to anxiety and brain inflammation

May 31, 2026
New study links parental indulgence to psychopathic and narcissistic traits in adulthood
Addiction

Childhood trauma and mental distress might shape the way fans idolize celebrities

May 30, 2026
“Only the tip of the iceberg:” Misophonia may reflect deeper psychological realities
ADHD Research News

More than half of adults with ADHD in clinical settings have a co-occurring personality disorder

May 30, 2026
Mystical beliefs predict a meaningful life even without organized religion
Borderline Personality Disorder

Deep-seated feelings of shame and abandonment fuel borderline traits in bipolar patients

May 29, 2026

Follow PsyPost

The latest research, however you prefer to read it.

Daily newsletter

One email a day. The newest research, nothing else.

Google News

Get PsyPost stories in your Google News feed.

Add PsyPost to Google News
RSS feed

Use your favorite reader. We also syndicate to Apple News.

Copy RSS URL
Social media
Support independent science journalism

Ad-free reading, full archives, and weekly deep dives for members.

Become a member

Trending

  • More than half of adults with ADHD in clinical settings have a co-occurring personality disorder
  • New study links parental indulgence to psychopathic and narcissistic traits in adulthood
  • How learning to read alters the brain’s approach to spoken language
  • The psychology of paradoxical thinking: Extreme arguments in favor of a controversial topic can reduce overall support
  • Men’s sexual desire peaks around age 40, large new study finds

Science of Money

  • Class isn’t dead: Your job title still predicts your wealth in Europe, a five-country study finds
  • Packing products tightly on shelves makes shoppers grab more flavors
  • When your job feels scriptable: How routine work and AI anxiety drain employee energy
  • Childhood obesity and the American Dream: New research links early weight to lower lifetime mobility
  • The brain chemical behind your money moves: How dopamine shapes financial choices

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