Impacts of multilevel factors on depressive symptoms among adolescents in South Korea

In this study, we used the social-ecological model to identify factors associated with the adolescents' depressive symptoms. We utilized data from the 6th year of the Korea Youth Panel Survey, which followed 4th year elementary school students nationwide from 2010 to 2016, and annual average PM2.5 data measured in each city/county/district throughout the country in 2015 by the Korea Meteorological Administration. Using multilevel analysis, we analyzed a total of 1,204 students in 57 communities. The null model analysis results identified regional differences in adolescents' depressive symptoms. Regarding individual and social factors at level 1, the conditional model analysis showed that gender, parental abuse, and negative relationships with teachers and peers had statistically significant associations with adolescents' depressive symptoms. Regarding community factors at level 2, it showed that more positive community awareness was related to lower levels of depressive symptoms among adolescents. In contrast, the analysis showed that adolescents living in communities with high levels of Particulate Matter (PM) 2.5 were more depressed. Based on these results, we recommend the provision of programs to improve relationships between parents, teachers, friends, and adolescents, and the implementation of intervention strategies to enhance community awareness and reduce air pollution to prevent and decrease adolescents' depressive symptoms.