The Effects of U.S. School Shootings on Indicators of Children’s Mental Health

More than 215,000 American children have experienced a school shooting since the Columbine High School massacre in 1999, and school shootings are substantially more common in the United States than in any other developed country. In recent years, these events have become more frequent and deadly. There have been 141 fatalities in 221 school shooting episodes between April 20, 1999 (Columbine High School in Littleton, CO) and May 25, 2018 (Noblesville West Middle School, Noblesville, IN), with more than half occurring since 2012, the year of the shooting at Sandy Hook Elementary School in Newtown, CT.

While school shootings receive widespread media coverage and incite public debates, there is little empirical research measuring their impacts on the mental health of children in affected communities. Past studies indicate that exposure to broadly defined assaultive violence (e.g., crime in the community or bullying at school) is associated with an increased incidence of adverse self-reported mental health outcomes, including post-traumatic stress disorder (PTSD), anxiety, depression, and internalizing and externalizing behaviors. Yet evidence specific to the effects of exposure to mass gun violence in school settings is limited. In their literature review of the mental health consequences of mass shootings, Lowe and Galea (2017) identified eleven peer-reviewed quantitative studies that examine shootings at three schools: an elementary school in Los Angeles, CA, in 1984, an elementary school in Winnetka, IL in 1988, and Columbine high school in Littleton, CO in 1999. These studies are limited in scope because they rely on small samples and often lack suitable control groups and/or pre-exposure data. Further, researchers often measure mental health with survey data, which can be subject to bias and measurement error due to under-reporting of mental health conditions.

We use large-scale prescription drug and insurance claims data to study how local exposure to school shootings influences indicators of children’s mental health, which we measure with prescriptions for anti-depressants and anti-anxiety medications, as well as outpatient and inpatient claims with mental health and external diagnoses. We use difference-in-difference and event-study designs to examine changes in outcomes of individuals residing in close proximity to schools with shootings in the two years after each shooting compared to the two years before, relative to comparison groups of individuals who reside further away from the shooting schools and individuals who reside in close proximity to observably similar schools that did not experience any shootings over our analysis time frame.

We find a large increase in anti-depressant prescription drug take-up among children under age 19 in the two years after a shooting with at least one fatality. We observe no evidence of pre-trends in prescription drug use, suggesting that our identified effects are driven by exposure to the shooting rather than by underlying mental health trends in the local area. Preliminary results also point to some increases in outpatient claims with mental health diagnoses.