Objective: To explore mediation of emotional regulation in the association between aggression behavior and non-suicide self-injury among rural middle school students. Methods: A multi-stage stratified random cluster sample of 14 291 middle school students from 15 cities in five provinces of China (Anhui, Yunnan, Guangdong, Heilongjiang, Hubei). A structured questionnaire was used to assess non-suicide self-injury, emotional regulation and aggressive. Results: During the past year, about 28.51% of participates reported self-injury, with 13.39% of them had 5 times or more. The five dimensions of aggressive behavior were positively correlated with non-suicide self-injury(P<0.01), emotional regulation was negatively correlated with non-suicide self-injury(P<0.01). The mediating effect of emotional regulation between aggression (physical aggression, verbal aggression, indirect aggression, anger and hostility) and non-suicide self-injury was found significant, the ratio of whose were 25.93%, 22.73%, 19.61%, 27.55% and 18.80%, respectively. Conclusion Emotional regulation plays a mediating role in adolescent self-injury and aggression, indicating self-injury and aggression could be prevented by enhancing emotional regulation among adolescents.

Objective: To explore the relationship between non-suicidal self-injury and Internet addictive behavior in adolescents. Methods: A cross-sectional survey of 15 538 middle school students across 5 provinces in China. Participants reported self- injury behavior during the past year and the Internet addition behaviors were assessed through Young’s Internet Addiction Test(IAT). Results: The prevalence of self-reported 1-year NSSI, Internet addictive behavior and pre-addictive behaviors was 28.7%, 3.3% and 29.9%, respectively. After controlling for potential confounders, the Internet addition was positively correlated with NSSI, and the risk of all types of NSSI was higher in adolescent with Internet addition than those with mild suspected Internet addictive behavior(OR=1.3-2.8). Conclusion These findings indicate that Internet addition is associated with the incidence of NSSI in adolescents.

Objective: To investigate the relationship between neglect , physical abuse and non-suicidal self-injury (NSSI) behaviors among middle school students in rural China. Methods: A total of 14 162 adolescents in Anhui, Guangdong, Yunnan, Heilongjiang and Hubei provinces were selected by multi-stage cluster random sampling method. Data were obtained on demographic information, neglect, physical abuse and non-suicidal self-injury from questionnaire survey. Results: During the past year before survey, 13.5% of participants engaged in self-injury 5 times or more, 15.4% of participants engaged in self-injury 1 to 4 times. Both neglect and physical abuse were significantly associated with self-injury in adolescents(P<0.01). After adjusted for gender, ethnicity, the only-one child, family structure, family economic status, and other variables, multinomial logistic regression showed that neglect and physical abuse were positively associated with self-injury behavior(OR=1.43-3.23). There was a potential dose-response relationship of accumulating physical abuse types and self-injury, with more physical abuse types, the higher risk of self-injury behavior. Conclusion Neglect and physical abuse experience should be considered as a risk factor for NSSI among adolescents in rural China. Specific intervention targeting neglect and physical abuse should be strengthened to reduce the occurrence of NSSI.