Abstract Mental health problems in adolescents often emerge alongside incidents of peer bullying, negatively affecting their development. In order to develop intervention measures for peer bullying among Chinese adolescents, the article elaborates on the current research progress in the theoretical basis, evidence based approaches, and practical models of peer bullying intervention, summarizes strengths and limitations of existing approaches, and proposes future research directions for intervention, with the aim of preventing and reducing peer bullying and creating a favorable environment for the healthy adolescent develpment.

Objective: To develop the Adolescent Peer Bullying Knowledge-Attitude-Practice (KAP) Questionnaire and to evaluate its reliability and validity, so as to provide an effective tool for evaluating the KAP level regarding peer bullying among adolescents. Methods: A preliminary framework was developed through literature review, expert consultation, and group discussions. In September 2024, 2 203 students in grades 7 to 9 from two regular junior high schools in Anhui Province were selected using cluster sampling for a preliminary survey aimed at questionnaire development, including item screening and reliability and validity testing. Results: The initial KAP questionnaire on adolescent peer bullying consisted of 25 items: two items, "Behavior 6" and "Behavior 7", were excluded as their correlation coefficients with the total KAP score being only 0.08 and 0.05, respectively, falling below the preset criteria(0.4). The final questionnaire comprised 23 items, divided into three dimensions: knowledge, attitude, and behavior. Reliability testing showed that the overall Cronbach α coefficient of the questionnaire was 0.89, with Cronbach α coefficients for the knowledge, attitude, and behavior dimensions being 0.91, 0.67 and 0.79, respectively. The overall splithalf reliability of the questionnaire was 0.87, with split half reliabilities for the knowledge, attitude, and behavior dimensions being 0.82, 0.64 , and 0.66, respectively. Testretest reliability ranged from 0.82 to 0.97. Confirmatory factor analysis results indicated that the questionnaire had RMSEA=0.062, NFI=0.924, CFI =0.931, with good discriminant validity. Conclusion The developed KAP questionnaire on adolescent peer bullying demonstrates good reliability and validity and can be used as an assessment tool for evaluating the KAP level regarding peer bullying among adolescents.

Objective: To evaluate the effectiveness of a family-school-community integrated intervention based on the microsystem theory in reducing peer bullying among junior high school students, so as to provide empirical evidence and feasible pathways for junior high school students bullying prevention and control in China. Methods: A combining convenience with clustering method was employed to select 6 268 students from three regular junior high schools in Fuyang and Anqing cities, Anhui Province, as the study subjects in October 2024, and randomly assigned by drawing lots to three groups: family-school-community integrated intervention ( n =2 063), school only intervention ( n =1 864), and control group ( n =2 341). From October 10, 2024, to January 10, 2025, the intervention was implemented for three months using posters, brochures, and videos, with one session every half month, each lasting 40 minutes. The family-school-community integrated intervention group received multi level interventions involving families, schools, and communities, while the school only intervention group received only school based interventions. The control group received routine school health education but no other interventions. Before and after the intervention, data on peer bullying among junior high school students were collected using the Peer Bullying Scale, and comparison of detection rate of peer bullying by Chi square test. Results: After the intervention,group comparison results showed that the incidence rates of various types of peer bullying in the family-school-community integrated intervention group, the school only intervention group, and the control group all showed statistically significant differences ( χ 2=28.61-66.85, all P <0.05). The detection rates of verbal bullying ( 7.51 %), relational bullying (5.62%), physical bullying (3.34%), cyberbullying (1.75%), being bullied (10.81%), verbal bullying others (2.67%), relational bullying others (1.55%), physical bullying others (1.36%), cyberbullying others (1.41%), and overall peer bullying (3.64%) in the family-school-community integrated intervention group were all lower than those in the control group (12.52%, 11.58%, 6.24%, 5.00%, 19.14%, 7.56%, 4.49%, 4.53%, 3.80%, 9.40%); additionally, the detection rates of verbal bullying others, overall peer bullying , verbal bullying, and being bullied , in the family-school-community integrated intervention group were all lower than those in the school only intervention group (4.67%, 6.65%, 13.14%, 16.42%), with statistically significant differences ( χ 2=30.04, 48.49, 19.75, 34.60, 58.89, 52.65, 31.32, 37.37, 24.14, 58.26; 11.25, 18.53, 33.93, 26.41, all P <0.016 7). Group comparison showed that in both intervention groups, the majority of peer bullying behaviors decreased after the intervention ( χ 2=4.86-171.01, all P <0.05). Conclusions The family-school-community integrated intervention based on the microsystem can effectively reduce peer bullying among junior high school students, with better efficacy than the single school intervention. The model can serve as a practical reference for establishing a multi level prevention and intervention system for junior high school students bullying in China.

Abstract Vitamin D, as an important nutrient, has been widely recognized for its significant role in the growth and development of children and adolescents, but its association with mental health is still under exploration. The article reviews and summarizes the related researches on vitamin D and common mental health problems of children and adolescents, including depression symptoms, anxiety symptoms, and suicidal ideation and behaviors, and possible biological mechanisms of vitamin D influencing mental health, to provide scientific evidence and ideas for improving the mental health of children and adolescents in China, as well as insights for future studies.

Objective: The study aimed to explore the relationship between childhood maltreatment (CM) and the Big Five personality traits of middle school students, so as to provide scientific evidence for promoting the healthy development of middle school students personality. Methods: A total of 5 724 middle school students from Xuancheng, Hefei and Huaibei of Anhui Province were selected by using a multi stage stratified cluster sampling method to conduct a questionnaire survey, including demographic characteristics, CM experience and Big Five personality traits. Linear regression analysis and canonical correlation analysis were used to explore the associations between CM and the Big Five personality traits. Results: Physical abuse, emotional abuse, sexual abuse, physical neglect, and emotional neglect of middle school students were significantly associated with conscientiousness ( β = -1.71 --2.55) and neuroticism ( β =1.93-3.87) personality traits( P <0.05). Except physical abuse, all other types of CM were significantly associated with extraversion ( β =-1.04--2.32) and agreeableness ( β =-1.07--1.37) personality traits( P <0.05), and only sexual abuse was associated with openness personality trait( β=-0.70, P <0.05). Except for openness personality trait, the relationship between the number of CM experience and the personality traits of middle school students was statistically significant; there was a dose response relationship between the number of CM experiences and the scores of personality traits each dimension( P < 0.05). In the canonical correlation analysis, the canonical correlation coefficient was -0.375( P <0.05). CM experiences were mainly reflected by emotional abuse, emotional neglect and physical neglect (canonical load coefficient was 0.556-0.951). The Big Five personality traits were mainly reflected by neuroticism, conscientiousness and extraversion (canonical load coefficient was -0.702 -0.639). Conclusion There is a correlation between CM and the personality traits of middle school students, and prevention of CM is of great significance for promoting the healthy development of middle school students personality.

Abstract Peer bullying in children and adolescents has become an significant public health concern in China. The Chinese government attaches great importance to bullying prevention in primary, secondary and high schools. However, it is still lack of systematic surveillance and effective intervention plans for peer bullying in children and adolescents. This paper analyzes the impact of peer bullying on current and lifelong health of children and adolescents, and describes current status of peer bullying surveillance in children and adolescents at the national level around the world. Meanwhile, this paper calls for strengthening the intervention against peer bullying from the perspective of ecosystem reconstruction intervention, thus preventing and eradicating peer bullying in children and adolescents.

Objective: To explore the mediating effect of depressive symptom on the relationship between peer bullying patterns and suicidal ideation, and to provide suggestions for school bullying and suicide prevention for adolescents. Methods: A follow up cohort was established in a junior middle school in Suixi County, Anhui Province in September 2019 (T1). The first follow up was conducted in September 2020 (T2). A total of 1 687 junior high school students participated in this study. Self designed peer bullying questionnaire,center for Epidemiological Studies Depression Scale for children,and questions regarding suicide related behaviors were administered. Results: Prevalence of suicidal ideation, victimization and bullying were 28.3%, 27.0% and 24.4%, respectively. The latent class analysis(LCA) identified three heterogeneous peer bullying classes: low aggressive victims(71.4%), high aggressive victims(3.3%), high verbal and relational aggressive victims( 25.3 %). The low aggressive victims class was used as the reference group, T1 depressive symptom mediated the association between high aggressive victims(mediating effect=0.43, P < 0.05 ), high verbal and relational aggressive victims class (mediating effect= 0.29 , P <0.05) and T2 suicidal ideation. Conclusion Depressive symptom plays a mediating role in the relationship between peer bullying and suicidal ideation. In order to prevent peer bullying and suicide related psychological behaviors of adolescents, educators should pay attention to adolescents mental health when formulating corresponding measures.

Objective: To explore the association between acute stress response during the outbreak of COVID 19 and peer bullying behaviors during the normalized management of COVID 19 among middle school students, and to provide a basis for developing relevant measures for peer bullying prevention. Methods: In December 2020, a total of 2 219 students from two junior middle schools in South Anhui(Xuancheng City) and North Anhui(Huaibei City), were selected to participate in this study by using the cluster sampling method. The occurrence of verbal bullying, relational bullying, physical bullying and cyberbullying behaviors among victims and perpetrators of bullying, and self rated acute stress response during the outbreak of COVID 19 (social isolation) were investigated. Multiple Logistic regression models were conducted to explore the relationship between different levels of acute stress response during the COVID 19 outbreak and peer bullying behaviors among middle school students. Results: The reported rate of peer bullying, being bullied by others and bullying others during the COVID19 normalized management were 65.8%, 63.8% and 27.1%, respectively. The reporting rate of verbal bullying victimization was the highest (54.8%) and cyberbullying others was the lowest (4.6%). The mean score of acute stress response among middle school students during the COVID 19 outbreak was (6.50±1.67). Except for physically bullying others, the reported rate of other bullying behaviors was the highest in the high level acute stress response group ( P <0.05). Multiple Logistic regression models showed that high levels of acute stress response were associated with high risk of verbal bullying victimization ( OR =1.38), relational bullying victimization ( OR =2.28), physical bullying victimization ( OR =1.87) and cyberbullying victimization ( OR =2.30) after adjusting for related confounders. In the high level acute stress response group, verbal bullying ( OR =1.80), relational bullying ( OR =1.99), physical bullying ( OR =1.76) and cyberbullying ( OR =2.32) had higher risks of bullying others than in the low level acute stress response group ( P <0.05). Conclusion High levels of acute stress response are associated with different peer bullying behaviors, with stronger associations with cyberbullying.

Objective: To explore the relationship between different types of bullying behavior and depressive symptoms among adolescents, and to provide scientific basis for further prevention of peer bullying. Methods: Based on the follow up data of 1 687 adolescents from Huaibei City, Anhui Province in September 2019 (T1) and September 2020 (T2), the autoregressive cross lagged analysis was employed to explore the relationship between different types of peer bullying and depressive symptoms. Results: The scores of bullying behaviors (physical bullying, verbal bullying, relational bullying and cyber bullying) and depressive symptoms at T2 were lower than those at T1,and the differences were statistically significant ( t =13.60, 8.61,7.24,3.76,8.29, P <0.01). There was a positive correlation between bullying behavior and depressive symptoms ( P <0.01). The results from cross lagged regression analysis showed that physical, verbal, relational and cyber bullying at T1 could positively predict depressive symptoms at T2 ( β = 0.06 , 0.04, 0.12, 0.05), and physical, verbal, relational and cyber bullying at T1 could positively predict depressive symptoms at T2 ( β =0.07, 0.10, 0.13, 0.10) ( P <0.05). Conclusion There were bidirectional associations between adolescent peer bullying and depressive symptoms.