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.

The association between tea consumption and blood pressure in the adult population in Southwest China.

OBJECTIVES: Prior research on the effect of tea consumption on blood pressure (BP) generated inconsistent findings. The objective of this study was to explore the effects of different types of tea consumption on BP. METHODS: We included 76,673 participants aged 30-79 from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Binary logistic regression was used to analyze the influences of different types of tea consumption on the risk of hypertensive BP. Moreover, multiple linear regression was used to examine the association between tea drinking and BP. RESULTS: Tea consumption was associated with a reduced risk of hypertensive BP by 10% (AOR: 0.90, 95%CI: 0.86-0.94). While dark tea was related to a 1.79-5.31 mmHg reduction in systolic blood pressure (SBP) and a 0.47-1.02 mmHg reduction in diastolic blood pressure (DBP), sweet tea, regardless of the duration, frequency, or amount of consumption, significantly was associated with a reduced SBP by 3.19-7.18 mmHg. Green tea also was associated with a reduced SBP by 1.21-2.98 mmHg. Although scented tea was related to reduced SBP by 1.26-2.48 mmHg, the greatest effect came from the long duration (> 40 years:ß=-2.17 mmHg, 95%CI=-3.47 mmHg --0.87 mmHg), low frequency (1-2 d/w: ß = -2.48 mmHg, 95%CI=-3.76 mmHg--1.20 mmHg), and low amount (≤ 2 g/d: ß=-2.21 mmHg, 95%CI=-3.01 mmHg--1.40 mmHg). Additionally, scented tea was correlated to a decrease in DBP at the frequency of 1-2 d/w (ß=-0.84 mmHg, 95%CI=-1.65 mmHg--0.02 mmHg). Drinking black tea only was associated with lowered SBP. The protective effect of black tea on SBP was characterized by the long-duration (> 15 years, -2.63--5.76 mmHg), high frequency (6-7 d/w, -2.43 mmHg), and medium amount (2.1-4.0 g/d, -3.06 mmHg). CONCLUSION: Tea consumption was associated with lower SBP and a reduced risk of hypertensive BP. The antihypertensive effect varies across types of tea consumed.

Depression and Deliberate Self-Harm Among Rural Adolescents of Sichuan Province in Western China: A 2-Year Longitudinal Study.

Objective: To explore the change in the prevalence and association of depression and deliberate self-harm and their common and independent influencing factors among western Chinese rural adolescents. Methods: A total of 2,744 junior and senior high school students from two rural schools in Sichuan Province, China, participated in the baseline survey and were invited to participate in two follow-up surveys. The Center for Epidemiologic Studies-Depression Scale, a deliberate self-harm item, the Social Support Rating Scale, the Rosenberg Self-esteem Scale and the Connor-Davidson Resilience Scale were administered. A bivariate four-level logistic regression model was used for analysis. Results: The prevalence of depression and deliberate self-harm were 39.6 and 21.2%, respectively. Regular physical exercise, a good relationship with parents, high resilience, and high self-esteem were common protective factors for both depression and deliberate self-harm. Feeling disliked by teachers was a common risk factor for both. Being female, having a mother who emigrated as a migrant worker before the student was 3 years old, feeling disliked by classmates and having a poor family economic status were associated only with an increased risk of depression. Participants with medium social support were less likely to report deliberate self-harm than those with low or high support. Depression and deliberate self-harm were clustered at the class level. Conclusions: The comorbidity of depression and deliberate self-harm in rural adolescents should be given ample attention. Interventions should consider the class clustering of depression and deliberate self-harm and their common and unique influencing factors.

Application of the health action process approach model for reducing excessive internet use behaviors among rural adolescents in China: a school-based intervention pilot study.

OBJECTIVE: There are few studies regarding Internet use behaviors of Chinese rural adolescents based on behavioral theory. The aim of this study is to examine the applicability and effectiveness of the health action process approach model (HAPA) in the intervention of excessive Internet use behaviors among rural adolescents in China. METHODS: Three hundred twenty-seven participants who met the excessive Internet use criteria were involved in this study. Four interventions based on the HAPA model were conducted during 2015-2017. The structural equation model (SEM) was applied to fit the HAPA model. RESULTS: The rate of average daily time spent online on weekends more than 4 h dropped from 57.2 to 39.1% (P < 0.001). The rate of daily game time more than 2 h decreased from 51.1 to 35.2% (P < 0.001). The result of SEM showed that both the applicability and effectiveness of the HAPA model were well in the intervention of excessive Internet use behaviors with good fitted indicators (χ2/df = 2.066, GFI = 0.889, CFI = 0.938, TLI = 0.928, IFI = 0.938, RMSEA = 0.057). The direct and indirect effects of the main pathways in the HAPA model were statistically significant (P < 0.05). The comparison analysis of HAPA model variables identified that outcome expectancy, intention, maintenance self-efficacy had been improved significantly after interventions. CONCLUSION: The intervention measures based on the HAPA model can effectively reduce excessive Internet use behaviors of Chinese rural adolescents, mainly through strengthen outcome expectancy, intention, and maintenance self-efficacy.

Research in physical exercise among rural adolescents based on the theory of planned behavior in Sichuan Province / 中国学校卫生

Objective@#To verify the applicability of the theory of planned behavior(TPB) in the physical exercise behaviors of rural adolescents in Sichuan Province, and to explore the possible influencing factors of physical exercise behaviors, and to provide a theoretical basis for further effective intervention measures.@*Methods@#A total of 2 302 students were selected from grade seven and grade ten of two rural middle schools in Zizhong, Sichuan Province. The survey was conducted with a structured questionnaire. Using TPB as the research framework and basis, the structural equation model was constructed for analysis.@*Results@#Lack of physical exercise was 1 527(66.3%).Physical exercise behavior was statistically different among schools, grades(t=-7.40，-2.90，10.90,P<0.05)， and genders. Based on TPB, the structural equation model was established and corrected to obtain the revised model, and the fitting index GFI=0.93, CFI=0.94, NFI=0.94, TLI=0.93, IFI=0.94,RMSEA=0.07, indicating the model fitted good. Exercise intention directly affected exercise behaviors. The standardized effect was 0.45(95%CI=0.39-0.52). Subjective norms and perceived power were the main two mediators of the relationship between value evaluation and exercise intention. The standardized effect values were 0.66(95%CI=0.57-0.73), 0.23(95%CI=0.16-0.93)(P<0.01).@*Conclusion@#There is serious lack of physical exercise in rural adolescents in Sichuan Province. TPB has a good applicability for physical exercise in rural adolescents in Sichuan Province. Subjective norm is the most important factors to promote exercise intentions.