Impacts of school shooter drills on the psychological well-being of American K-12 school communities: a social media study

Firearm fatalities are a major public health problem in the United States, with K-12 school shootings occurring more frequently than in most other nations. While school shootings remain rare compared to daily gun violence, each incident is alarming and affects communities that view schools as safe spaces. In recent years, calls for improved school safety and preparedness, especially for active-shooter incidents, have spurred widespread implementation of drills. By 2015–16, 95% of public schools conducted lockdown procedures, with at least 40 states requiring drills. Despite this, there is limited guidance on drill content and implementation, and terms like “lockdown drills” and “active-shooter drills” are often conflated. Drills vary dramatically, from simple lockdown practices to unannounced simulations with actors and simulated gunfire. Existing research is mixed and largely limited to individual schools or short-term outcomes, with unclear evidence on whether drills save lives and little understanding of long-term mental health impacts on students, teachers, and parents. Given that most students will experience drills, and that developmentally sensitive responses are critical during formative years, this study seeks to provide empirical evidence on long-term and widespread mental health impacts of school shooter drills using large-scale social media data and focus group triangulation.

Prior studies of school shooter drills have relied on behavioral observations and surveys to assess compliance with instructions and immediate perceptions. Results are mixed: some studies show improved performance on certain lockdown tasks (e.g., turning off lights, locking doors), while others show continued difficulties (e.g., hiding, remaining silent). Perceived preparedness sometimes increases immediately after drills, but other work reports decreased feelings of safety, increased fear, and concerns that drills inform potential perpetrators. Methodological limitations include small samples, single-school or district studies, short-term measurements, and lack of standardized drill definitions or protocols, limiting generalizability. Few studies explicitly examined active-shooter scenarios in protocols, potentially underestimating emotional harms. There is also a lack of research on long-term psychological impacts and on behavioral manifestations beyond self-reports. Computational social science has demonstrated that social media language can reflect psychological states and community responses to crises, and quasi-experimental designs using social media can approximate causal inference where RCTs are infeasible. This study builds on these literatures by analyzing large-scale, longitudinal social media data around documented drill events, complemented by focus groups to contextualize findings.

Design: Observational, quasi-experimental study using social media data and interrupted time series (ITS) analysis, with multiple robustness checks, plus qualitative focus group triangulation. Data on drill events: A survey (Nov 2019–Feb 2020) of volunteers from a grassroots gun violence prevention organization identified drill dates and locations for K-12 schools between April 2018 and Dec 2019, including school grade, name, and location (no PII collected). From 153 responses, 138 schools across 37 states were identified (63 elementary, 35 middle, 18 high, 21 uncategorized; 130 public/charter/pre-K; 8 private). For social media analyses, 114 of these schools had sufficient data. Social media datasets: Collected public posts spanning 90 days before and 90 days after each drill. Three collection strategies: (1) Twitter posts by users following the school’s official account (network homophily), (2) Twitter posts by users with self-reported geo-location within the school district, and (3) Reddit posts in communities associated with school names or local neighborhoods/cities. Total analyzed: 27.8M posts from 542,270 unique users for 114 schools in 33 states (Jan 2018–Mar 2020). A control dataset comprised ~27M random tweets from Twitter’s 1% public stream, geo-located outside the 114 school districts, covering matched Before/After windows, yielding ~54M posts overall. Outcomes: Two dimensions were measured. - Mental health symptomatic expressions: Machine-learning classifiers (binary SVMs with n-grams, transfer learning from Reddit) identified stress, anxiety, and depression expressions (trained on r/stress, r/anxiety, r/depression vs. 20 non-mental-health subreddits). Reported average accuracy ~0.90; transfer agreement on Twitter ~87%. Given comorbidity, stress and anxiety were combined as a single outcome (high symptomatic expression if either/both present). - Psycholinguistic expressions (LIWC): Non-affective categories used included cognition and perception (percept), interpersonal focus (e.g., 1st person plural, 2nd person pronouns), temporal references, lexical density and awareness (article use), and social/personal concerns (e.g., friends, work). Temporal analysis (ITS): For each outcome, constructed daily time series over 180 days (90 Before/90 After). Normalized using z-scores. Fitted separate linear trends for Before and After periods. Immediate change (IC) computed as difference in intercepts at the drill date (time zero). Longer-term change (LC) computed as the relative change in mean proportion of posts exhibiting an outcome in After vs. Before periods. Statistical significance assessed via Welch’s t-tests with Benjamini–Krieger–Yekutieli FDR correction. Causality and robustness checks: 1) Temporal alignment and exclusion of confounds: Aligned posts by offsets to each school’s drill date to mitigate seasonal/school-specific confounds. Isolated effects of mass shooting events by excluding schools with temporal overlap (same month) or spatial overlap (same state during analysis window) with mass shootings (defined as 4+ injured/killed), and re-estimated outcomes. 2) Counterfactual forecasting: Trained ARIMA models on Before period for stress/anxiety and depression to forecast After period under a no-drill assumption; compared predicted vs. actual After outcomes. 3) Synthetic control via permutation: Generated 1000 synthetic time series per outcome with similar distributions; computed LC around placebo drill dates (midpoint) and compared with actual LC to obtain p-values (probability synthetic LC exceeds actual LC). 4) Actual control comparison: Constructed control time series from non-school-specific Twitter data, aligned by school drill offsets, and compared LC and correlations to treatment. Focus group triangulation: Six 1-hour semi-structured focus groups (Zoom) with 34 participants (21 parents, 11 teachers, 2 students; mostly female). Eligibility: age ≥15; participation in or parent of a child participating in at least one drill in 2018–2019. Sessions recorded with consent, transcribed, de-identified, and analyzed via inductive semi-open coding by two coders (psychology and computing backgrounds). A 15-code codebook guided thematic analysis to contextualize quantitative findings. IRB approval obtained; informed consent/assent procedures followed.

Mental health impacts: - Stress/anxiety LC: Increased from 0.281 (Before) to 0.399 (After), a 42.1% relative increase (t=19.1, p<1e-15). Immediate change (IC, z-score): 0.936; After slope sustained (0.00144). - Depression LC: Increased from 0.125 (Before) to 0.173 (After), a 38.7% relative increase (t=10.13, p<1e-15). IC (z-score): 0.545; After slope increased (0.0053). - Lexical saliency (SAGE): Before-drill high stress/anxiety and depression posts featured more positive words (e.g., proud, grateful, excited). After-drill posts showed increased references to home, school, kids, community, help, support, need, family, indicating concern and calls for support. Psycholinguistic and community outcomes (LIWC): - Perception words: LC +10.78% (t=3.6, p<1e-4); IC +0.084. - Article use (lexical density/awareness): LC +16.3% (t=9.5, p<1e-15); IC +0.353. - Interpersonal focus: 1st-person plural pronouns LC +47.79% (t=8.1, p<1e-15); 2nd-person pronouns LC +10.21% (t=3.1, p<0.01). ICs positive across these categories (0.423–1.175). - Social/personal concerns: Friends LC +33.7% (t=3.5, p<1e-4); Work LC +106.18% (t=18.3, p<1e-15). ICs positive. - Interpretation: Results indicate heightened sense-making, awareness, solidarity, and civic/community engagement following drills, concurrent with worsened mental health markers. Causality and robustness: - Excluding mass shooting overlaps: Temporal overlap removal (31 drills; ~1.5M posts) yielded LC +43.12% (stress/anxiety, p<0.001) and +39.58% (depression, p<0.001). Spatial overlap removal (41 drills; ~10.7M posts) yielded LC +30% (stress/anxiety, p<0.001) and +29.6% (depression, p<0.001). Effects persisted. - Counterfactual ARIMA: Predicted After series were 26.3% (stress/anxiety) and 50% (depression) lower than actual After levels (RMSE 0.14 and 0.09; p<0.001), indicating drills likely caused the increases. - Synthetic permutation tests (1000 perms): Probability that placebo LC exceeds actual LC was extremely low: p=0 for stress/anxiety, depression, article, first-person plural, second-person, work; p=0.021 for perception; p=0.013 for friends; all p<0.05. - Actual control comparison: Control LC changes were only 0.375–2.5% (often nonsignificant; 0.36≤p≤0.77 except modest effects for stress/anxiety 0.3%, work 2.5%, perception 0.43%), versus treatment LC 10.2–106.18%. Control 0-lag cross-correlations 0.593–0.988 vs. treatment −0.009 to 0.043, supporting attribution to drills. Subgroup analyses: - Patterns held across teachers, students, parents and across school levels. High school communities and teachers exhibited the largest changes: worsened mental health +55.1% to +124.3% (p<0.001) and elevated LIWC community outcomes +15.9% to +27.2% (p<0.001). Focus group corroboration: - Participants reported acute distress during and after drills (panic attacks, fear, persistent nervousness), and increased discussions/advocacy within communities. Some normalization/desensitization was also noted.

Findings show that school shooter drills, though intended to enhance preparedness, are associated with substantial and sustained increases in stress/anxiety and depression expressions within school communities, lasting at least 90 days post-drill. Linguistic changes indicate heightened sense-making, vigilance, and collective engagement. The absence of comparable changes in controls, persistence after exclusion of overlapping mass shooting events, counterfactual forecasting differences, and permutation tests strengthen causal interpretation that drills contribute to these observed effects. Focus group narratives align with computational findings, describing fear, confusion, and lingering distress, alongside increased collective conversations and advocacy. Methodologically, leveraging large-scale, naturalistic social media data with ITS and multiple robustness checks offers scalable evidence beyond small-sample, short-term, self-report studies, adding clarity to a literature with mixed findings. Practically, results raise concerns about the psychological costs of unregulated drills, suggesting the need to balance preparedness with mental health impacts and consider alternative, evidence-supported safety strategies.

This study provides the first large-scale, longitudinal evidence that current, unregulated K–12 school shooter drills are associated with significant, lasting negative impacts on the psychological well-being of school communities, while simultaneously catalyzing increased communal engagement and discourse. Using 54 million social media posts around verified drill dates and multiple robustness checks, we demonstrate increases of approximately 39–42% in stress/anxiety and depression, and 10–106% in psycholinguistic markers of engagement. We recommend rethinking drill design and utility in favor of proactive, evidence-based safety strategies (e.g., fostering positive school climate, expanding access to mental health resources, and employing multidisciplinary threat assessment programs). If drills are conducted, they should follow trauma-informed best practices (advance notification, avoid realistic simulations, ensure developmental appropriateness, consult mental health professionals, and track outcomes). Future research should examine longer-term effects beyond 3 months, potential chronicity, differential impacts by drill types and implementations, incorporate additional causal inference techniques, and ethically include younger student perspectives.

- Observational design limits definitive causal inference despite multiple robustness checks; results should not be taken as clinical diagnoses. - Mental health classifiers, though validated, infer symptomatic expressions from language and cannot replace clinical assessment. - Analysis window limited to 90 days Before/After; longer follow-up needed to assess chronic effects. - Potential self-selection and platform biases: relies on users active on social media; Twitter restricts users under 13, possibly underrepresenting younger students. - Broader community sample includes indirect stakeholders (parents, caregivers, community members), which may dilute or confound direct effects but reflects real community impact. - Survey did not capture specific drill types or implementation details; effects may vary by protocol and realism. - Possibility of multiple drills within analysis windows is low but not impossible; future work should model rapid-succession drills explicitly.