AUTHOR=Lei Hui , Xiong Jingru , Rao Yuling , Zhu Ting , Zhang Xiaocui TITLE=Relationships among self-esteem, depression and self-injury in adolescents: a longitudinal study JOURNAL=Frontiers in Public Health VOLUME=Volume 12 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1406283 DOI=10.3389/fpubh.2024.1406283 ISSN=2296-2565 ABSTRACT=Objective: Non-suicidal self-injury is a widespread mental health concern among adolescents. This study aimed to examine the relationship between self-esteem, depression, and self-injury among adolescents using a longitudinal research design. Methods: The Self-Esteem Scale (SES), Child Depression Inventory (CDI), and Adolescent Self-Injury Scale (ASIS) were used to follow up 1265 junior middle school students on three occasions with six-month intervals. Results: At all three time points, there were significant gender differences in self-esteem, depression, and self-injury. Self-esteem was negatively correlated with depression and self-injury at all three time points, while depression and self-injury were significantly positively correlated. Cross-lagged analysis revealed that self-esteem at Time 1 (T1) did not significantly predict self-injury at Time 2 (T2), but self-esteem (T2) significantly predicted self-injury at Time 3 (T3; β=-0.079, p<0.05). Similarly, selfinjury (T1) significantly predicted self-esteem (T2; β=-0.140, p<0.001), and self-injury (T2) significantly predicted self-esteem (T3; β=-0.071, p<0.01). Horizontal and longitudinal mediating analysis showed that depression served as a complete mediator in both the pathway from self-esteem to self-injury and from self-injury to self-esteem. Cross-lagged analysis showed that self-esteem (T1) significantly predicts depression (T2; β=-0.070, p<0.05), which in turn predict self-injury (T3; β=0.126, p<0.001). Similarly, self-injury (T1) predicted depression (T2; β=0.055, p<0.05), which further predicted self-esteem (T3; β=-0.218, p<0.001).The self-esteem, depression, and self-injury of adolescents are closely related; selfesteem and self-injury predict each other; self-esteem indirectly affects self-injury through depression; and self-injury indirectly affects self-esteem through depression. Based on the relationship of bidirectional prediction of self-esteem and self-injury mediated by depression, this study proposes a theoretical model of depression-mediated self-esteem and self-injury cycle.