Psychotic symptoms in mass shootings v. mass murders not involving firearms: findings from the Columbia mass murder database

Victimology of Mass Shootings and Mass Murders Not Involving Firearms

Most research to date has focused on perpetrators of mass murder incidents. Hence, there is little information on victims. We examined 973 mass murders that occurred in the United States between 1900 and 2019 resulting in 5,273 total fatalities and 4,498 nonfatal injuries for a total of 9,771 victims (on average 10 victims per incident). Approximately 64% of victims of mass murder were White individuals, 13% were Black individuals, 6% were Asian individuals, and 14% were Latinx individuals. Given the higher number of nonfatal injuries per non-firearm mass murder event (11.0 vs. 2.8, p < .001), the total number of victims was only 50% higher for mass shootings (5,855 victims) vs. non-firearm mass murder events (3,916 victims). Among the 421 incidents of mass murder in the United States since 2000, Black, Asian, and Native American individuals were overrepresented among victims of mass shootings compared with their representation in the general U.S. population, and White individuals were underrepresented (all p ≤ .002). Findings of racial/ethnic differences were similar among victims of mass murder committed with means other than firearms for Black, Asian, and White individuals. These findings highlight different areas of victimology within the context of these incidents.

Mass Violence and the Complex Spectrum of Mental Illness and Mental Functioning

Importance

Psychiatry has struggled to clarify the types of mental turmoil that are associated with mass violence. While the problem is complex, it may present an opportunity to improve research, as well as inform public dialogue about what types of mental illness are actually associated with such mass tragedies.

Observations

Assuring the diagnostic accuracy of those who commit mass violence is challenging due to the retrospective nature of the analysis and lack of reliable psychiatric data. Psychiatric research has begun to use a dimensional approach that may be well suited to the study of mental illness in perpetrators of mass violence. This approach aggregates psychiatric symptoms into 3 domains of psychopathology: (1) internalizing, (2) externalizing, and (3) psychotic experience. This approach has practical clinical use and research support. A dimensional approach may help clear up misconceptions about the rate of psychosis in mass violence perpetrators, as well as reveal the most common dimensions of mental functioning associated with perpetrators.

Conclusions and Relevance

Improved research methods are needed to clarify and prevent mass violence. More precisely identifying the symptoms and mental turmoil of perpetrators may be associated with improved early identification and prevention. Because adolescence is a critical and formative period in which internalizing and externalizing problems arise, early interventions may have the best chance of reducing future mass violence.

Mass murders involving firearms and other methods in school, college, and university settings: Findings from the Columbia Mass Murder Database

While mass murders involving academic settings, especially using firearms, are of grave, growing public concern, identifying consistent patterns to aid prevention has proved challenging. Although some characteristics, such as male sex, have been routinely associated with these events, another hypothesized risk factor, severe mental illness, has been less reliably predictive. We isolated cases of mass murder perpetrated at least in part at schools, colleges, and universities from the Columbia Mass Murder Database (CMDD) and categorized them by location (within or outside of the US), and whether firearms were used. Demographic similarities and differences between groups were analyzed statistically wherever possible. We examined 82 incidents of mass murder, by any means, involving academic settings. Nearly half of all incidents (47.6%), and most involving firearms (63.2%), were U.S.-based, whereas those not involving firearms largely occurred elsewhere (88.0%). Consistent with previous reports, perpetrators of mass shootings involving academic settings are primarily Caucasian (66.7%) and male (100%). Severe mental illness (i.e., psychosis) was absent in the majority of perpetrators (firearms: 80.7%; nonfirearms: 68.0%). About half (45.6%) of mass school shootings ended with the perpetrator's suicide. When present, psychotic symptoms are more associated with mass murders in academic settings involving means other than firearms. The question of whether perpetrators of such incidents may perceive their actions as a kind of final act might enhance policy development and/or how law enforcement intervenes.

Evaluating threats of mass shootings in the psychiatric setting

Psychiatrists may encounter patients at risk of perpetrating mass shootings or other mass violence in various settings. Most people who threaten or perpetrate mass violence are not driven by psychiatric symptoms; however, psychiatrists may be called upon to evaluate the role of mental illness plays in the risk or threat, and to treat psychiatric symptoms when present. Regardless of whether psychiatric treatment is likely to reduce symptoms or the potential for violence, the psychiatrist should collaborate closely with law enforcement, potential targets, and other agencies involved to mitigate risk. Such communications are governed by various privacy laws and duties to third parties. Additional measures, like protective orders, may be a means of restricting the subject's access to firearms.

Structural competency and the future of firearm research

In this critical literature review we develop a five-part agenda for pandemic-era research into mass shootings and multiple-victim homicides that promotes understanding the psychologies of individual shooters within larger structures and systems. We show how the momentous events set in motion by the COVID-19 virus, and the structural drivers of inequity and racism that its spread exposed, challenge mental health research on gun trauma to better account for broader terrains of race and place, as well as the tensions, politics, and assumptions that surround guns in the U.S. more broadly. Doing so will broaden mental-health interventions into epidemics of U.S. gun trauma, and challenge mental health research better recognize structural biases inherent in its own purview. We frame the agenda through the rubric of structural competency, an emerging framework that systematically trains health care professionals and others to recognize ways that institutions, neighborhood conditions, market forces, public policies, and health care delivery systems shape symptoms and diseases. Developing a structural framework around research into U.S. gun violence addresses the risks, traumas, meanings, and consequences that firearms represent for all communities-and highlights the importance of a renewed focus on mental health and safety for communities of color. Recognizing how gun violence reflects and encapsulates structures helps mental health experts address common sense gun policies within broader contexts-by fighting against structural racism or racially inflected gun policies for instance, or against economic policies that undermine access to mental health care more broadly.