A cross-sectional study of the association between physical activity and depressive symptoms among adolescents in southwest China stratified by parental absence: the mediating role of insomnia and the moderating role of resilience.

OBJECTIVES: This study explored the mechanisms by which physical activity was associated with depressive symptoms in multi-ethnic (Han, Yi and Tibetan) adolescents in southwest China. The mediating role of insomnia in the association of physical activity with depressive symptoms, the moderating role of resilience in this mediation model and the moderating role of parental absence in the moderated mediation model were also examined. DESIGN: A cross-sectional survey. SETTING: In southwest China (Sichuan Province and Tibet Autonomous Region). PARTICIPANTS: 3195 adolescents from a school-based survey conducted between April and October 2020. METHODS: There were 3143 valid samples in this study (47.2% males with mean age=12.88±1.68 years). Structural equation models were developed to estimate the direct and mediating effect, and the moderating effect. Multigroup comparison was performed to examine the differences and similarities of the moderated mediation model across three parental absence subgroups: (1) both parents present, (2) one parent absent and (3) both parents absent. RESULTS: As hypothesised, physical activity was significantly and positively associated with the reduction of depressive symptoms in adolescents. Insomnia partially mediated the effect of physical activity on depressive symptoms. In addition, resilience moderated the direct and indirect effects of physical activity (through insomnia) on depressive symptoms. Finally, the multigroup comparison indicated the moderating effect of parental absence on the moderated mediation model. CONCLUSIONS: Physical activity was associated with alleviating insomnia symptoms among adolescents, thus correlating with the improvement of their depressive symptoms. Resilience was associated with enhancing the beneficial effects of physical activity, further improving depressive symptoms among adolescents, especially those with both absent parents. It is evident that physical activity interventions should be further incorporated into public health programmes to foster the physical and mental health of left-behind adolescents in southwest China.

Negative life events and suicidality among adolescents in Western China: the mediating effect of depressive symptoms and the moderating effect of self-esteem.

OBJECTIVE: To investigate the mediating role of depressive symptoms in the relationship between negative life events (NLEs) and suicidality, as well as to test the moderating effect of self-esteem in the mediation model. METHODS: A total of 3,003 adolescents from Han, Tibetan, and Yi ethnic groups living in Western China were included in this study. Utilizing the structural equation model, a mediation model and a moderated mediation model were constructed. RESULTS: The presence of NLEs was positively associated with suicidality (ß = 0.17, p < 0.001). Depressive symptoms partially mediated the relationship between NLEs and suicidality (indirect effect ß = 0.19, p < 0.001). Self-esteem moderated both the antecedent and subsequent segments of the mediating paths of "NLEs → depressive symptoms → suicidality" and the direct relationship between NLEs and suicidality. Among adolescents with a low level of self-esteem, the mediating effect coefficient of depressive symptoms was higher at 0.18 (95% confidence interval (CI): 0.14-0.23), in contrast to adolescents with a high level of self-esteem, where the mediating effect coefficient of depressive symptoms was 0.04 (95% CI: 0.02-0.07). CONCLUSION: NLEs are directly associated with an increased risk of suicidality and indirectly related to suicidality by increasing the risk of depressive symptoms among adolescents. Self-esteem can moderate the mediating effect of depressive symptoms and the relationship between NLEs and suicidality. The intervention strategy for preventing suicidality among adolescents who have experienced NLEs should focus on reducing depressive symptoms and improving self-esteem.

Internet addiction and depressive and anxious symptoms among Chinese rural left-behind adolescents: Mediating roles of resilience and friendship quality.

BACKGROUND: Rural left-behind adolescents are more vulnerable to Internet addiction and depressive and anxious symptoms due to the lack of family support and parental supervision. This study was the first to investigate the longitudinal relationships between Internet addiction and depressive and anxious symptoms and to examine the mediating roles of resilience and friendship quality in rural left-behind adolescents. METHODS: Included in this study, which was from a longitudinal study conducted five times over 2 years, were 1001 rural left-behind adolescents. The internationally used scales for depressive and anxious symptoms, Internet addiction, resilience and friendship quality were administered. A structural equation model was used for analysis. RESULTS: The prevalence of Internet addiction, depressive and anxious symptoms among rural left-behind adolescents were 17.7%, 35.8% and 27.6%, respectively. Internet addiction predicted the later depressive and anxious symptoms (ß = 0.200, 95% confidence interval [CI]: 0.116-0.274 and ß = 0.263, 95% CI: 0.188-0.330). Resilience acted as an independent mediator in the relationships between Internet addiction and depressive and anxious symptoms (ß = 0.037 and 0.034, P < 0.01). Resilience and friendship quality played a chain-mediating role on the longitudinal relationships between Internet addiction and depressive and anxious symptoms (ß = 0.011 and 0.010, P < 0.001). The mediating effects accounted for 24.0% and 16.7% of the total effects, respectively. CONCLUSION: Resilience and friendship quality play an independent or chain-mediating role in longitudinal relationships between Internet addiction and depressive and anxious symptoms. The findings inform targeted intervention strategies to improve the mental health of left-behind adolescents.

The association between physical activity and subjective well-being among adolescents in southwest China by parental absence: a moderated mediation model.

OBJECTIVES: Built on the Positive Youth Development (PYD) framework, this study examined how physical activity affected the subjective well-being of adolescents in the multi-ethnic area of southwest China. The mediating role of school connectedness as an external development asset and the moderating role of resilience as an internal development asset were specified and tested within the framework of sport-based PYD. METHODS: A cross-sectional survey of 3143 adolescents (47.2% boys with mean age = 12.88 and SD = 1.68) was conducted in 2020. A structural equation model (SEM) was developed to estimate the direct effect of physical activity, the mediating effect of school connectedness, and the moderating effect of resilience on adolescents' subjective well-being. Multi-group comparison was made to investigate differences and similarities across three parental absence subgroups: (1) both parents present, (2) one parent absent, and (3) both parents absent. RESULTS: As surmised, physical activity, school connectedness, and resilience all positively and significantly affected adolescents' subjective well-being. SEM analyses revealed that school connectedness mediated the effect of physical activity on subjective well-being. Moreover, resilience moderated both the direct and indirect effects of physical activity (through school connectedness) on subjective well-being. Finally, the multi-group comparison revealed a moderating effect of parental absence on the moderated mediation model. LIMITATIONS: This study is a cross-sectional survey, so inference of causal associations among the study variables is impossible. CONCLUSIONS: Healthy lifestyle behaviors, school-supportive settings, and positive individual development assets can enhance the subjective well-being of adolescents in southwest China, especially those whose parents were absent. Physical activity interventions informed by the PYD framework should be incorporated into public health programs designed to foster the physical and mental health of left-behind adolescents in southwest China.