RÉSUMÉ
BACKGROUND: It is unclear how exposure to and perception of community trauma creates a mental health burden. This study aimed to examine the psychological distress trends among community residents in acute stress reaction, acute stress disorder, and post-traumatic stress disorder phases following the Seoul Halloween crowd crush. METHODS: A three-wave repeated cross-sectional survey was conducted with participants after the incident. Analysis of covariance (ANCOVA) with post hoc Bonferroni test was adopted to examine temporal changes in psychological distress and psychological outcomes resulting from media impacts. A two-way ANCOVA was adopted to examine the interaction effects of time and relevance to victims on psychological distress. RESULTS: A total of 807, 1,703, and 2,220 individuals participated in the three waves. Anxiety (estimated mean [standard error of the mean]: 2.28 [0.03] vs. 2.12 [0.02] vs. 2.03 [0.02]; P < 0.001), depression (2.22 [0.03] vs. 2.01 [0.02] vs. 1.90 [0.02]; P < 0.001), and anger (2.70 [0.03] vs. 2.66 [0.02] vs. 2.49 [0.02]; P < 0.001) gradually improved. However, sense of safety initially worsened and did not recover well (2.96 [0.03] vs. 2.75 [0.02] vs. 2.77 [0.02]; P < 0.001). The interaction effect of time and relevance to the victim were significant in depression (P for interaction = 0.049), anger (P for interaction = 0.016), and sense of safety (P for interaction = 0.004). Among participants unrelated to the victim, those exposed to graphics exhibited higher levels of anxiety (2.09 [0.02] vs. 1.87 [0.07]; P = 0.002), depression (1.99 [0.02] vs. 1.83 [0.07]; P = 0.020), and anger (2.71 [0.03] vs. 2.47 [0.08]; P = 0.003) at W2 and higher anger (2.49 [0.02] vs. 2.31 [0.06]; P = 0.005) at W3. CONCLUSION: Community residents indirectly exposed to trauma also experienced psychological distress in the early stages after the incident. A significant impact of media which might have served as a conduit for unfiltered graphics and rumors was also indicated.