LAUSR

BACKGROUND In 2016, two consecutive moderate magnitude earthquakes occurred in Ulsan, South Korea. Therefore, we aimed to investigate the impact of earthquakes on the mental health of residents in Ulsan. METHOD We used data from the 2015-2017 Korean Health Insurance Review & Assessment Service National Patient Sample. We conducted an interrupted time series analysis using location-based controls. Changes in the number of antidepressants, benzodiazepines, and zolpidem prescriptions in Ulsan were compared to controls. Overall changes in weekly prescriptions one year after the first earthquake, compared to a non-earthquake scenario, were estimated. RESULTS In antidepressant prescriptions, the increase in trend after an earthquake was significantly higher than controls. However, the changes in benzodiazepines and zolpidem were not significant. Overall, the impact of the earthquake on weekly antidepressant prescriptions at one year was estimated as a 1.32 (95% CI: 1.18 - 1.56) rate ratio compared to the non-earthquake scenario. This corresponded to a 1,989.7 (95% CI: 1,202.1 to 3,063.0) increase in the number of prescriptions. Among subgroups, the increase was highest among males aged 20-39 years. CONCLUSION The moderate earthquake in Ulsan was associated with an increase in antidepressant prescriptions. The increase in the male group aged 20-39 was the highest. The impact may vary according to the context of the population.