Objective: To investigate the prevalence of depression and anxiety and its relationship with bullying and violent behaviors among middle school students in Beijing, so as to provide a scientific basis for promoting the mental health of middle school students. Methods: A total of 18 379 junior high school, general high school, and vocational high school students from 16 districts of Beijing were selected by stratified cluster random sampling from September to November, 2023. The χ2 test was used to analyze the depression or anxiety symptom and injuryrelated behaviors such as bullying among middle school students. Logistics regression was used to analyze the correlation between depression or anxiety symptom and injury correlation behaviors among middle school students. Results: The detection rates of depression symptoms and anxiety symptoms were 18.2% and 8.6% among middle school students in Beijing, and the comorbidity was 7.6%. The reporting rate of school bullying was 3.3%. The results of Logistic regression showed that girls (OR=1.23), high school students (OR=1.85) and vocational high school students (OR=1.91), school bullying (OR=3.83), being scolded and beaten by parents (OR=3.32) and being exposed to cyber violence (OR=4.43) were positive factors related to depression symptoms; and nonresidential students (OR=0.87) was a negative factor related to depression symptoms (P<0.05).Girls (OR=1.32), high school students (OR=1.77) and vocational high school students (OR=1.50), school bullying(OR=3.63), being scolded and beaten by parents (OR=3.41) and being exposed to cyber violence (OR=3.33) were positive factore related to anxiety symptoms (P<0.05). Conclusions The depression and anxiety symptoms among middle school students in Beijing are closely related to the behaviors of school bullying and experiencing violence from parents or the Internet. Various measures should be taken to reduce the situation of school bullying, being scolded and beaten by parents and cyber violence among middle school students to promote their mental health.

Objective: The study was aimed at exploring the latent classes and factors influencing middle school students health risk behaviors in Beijing, so as to provide a scientific basis for determining key intervention targets and formulating relevant intervention measures. Methods: A questionnaire survey was conducted among 17 730 junior middle school, senior high school and vocational high school students in 16 districts of Beijing from October to December 2022. Six types of health risk behaviors were assessed with latent class analysis, including unhealthy diet, lack of exercise, unintentional harm, intentional harm, substance abuse and Internet addiction behavior. Results: The latent classes of health risk behavior among middle school students in Beijing were divided into three classes:high risk behavior (961 participants, 5.42%), low lack of exercise/high intentional injury (1 099 participants, 6.20%), and low risk behavior (15 670 participants, 88.38%). Disordered multiple Logistic regression analysis indicated that middle school students who were male ( OR =1.45), in high school ( OR =2.00), had other family types ( OR =1.90), possibly had depressed feelings ( OR =2.27), had depressed feelings ( OR =6.18), or were absent from school because of illness in the past year ( OR =1.79) were more likely to be in the high risk than the low risk behavior group. Moreover, middle school students who were male ( OR =2.30), had an extended family ( OR =1.18), had a reorganized family ( OR =1.70), had other family types ( OR =1.94), possibly had depressed feelings ( OR =3.10), had depressed feelings ( OR =4.91), had taken sick leave in the prior 2 weeks ( OR =1.54), or had absence from school because of illness in the past year ( OR =1.71) were relatively more likely to be in the low lack of exercise or high intentional injury group ( P <0.05). Conclusion Clear latent classes of health risk behaviors among middle school students are found to be present in differing proportions in Beijing. Relevant departments should take targeted intervention measures in a timely manner to reduce the occurrence of health risk behaviors among middle school students.

Objective: To analyze high myopia and dioptre changes in middle school students in Beijing from 2019 to 2022, so as to provide a basis for formulating preventive and control measures. Methods: Using stratified cluster random sampling, 16 districts of Beijing were divided into four groups, each of which was respectively composed of 83, 83, 84, and 84 middle schools, in order to examine non cycloplegic auto refraction among the senior grades 1 to 3 students from September to October in each year (from 2019 to 2022). Finally, the dataset results of each of the four groups (21 589, 21 161, 21 561, 21 123) were compared by the Chi square test and trend Chi square test. Trend changes were evaluated by annual percentage change (APC). Results: The rates of high myopia were higher in female students than in males from 2019 to 2022 (15.60%,14.59%; 15.33%, 14.44%; 14.65 %, 14.17%; 14.63%,13.84%), and the difference in 2019 was statistically significant ( χ 2=4.93, P <0.05). The rates of high myopia in middle school students in urban areas were significantly higher than those in rural areas(16.45%, 13.78%; 16.81 %, 13.00%; 15.84%, 13.06%; 15.85%, 12.72%), and the differences were statistically significant ( χ 2=30.18, 60.43, 33.92 , 42.23, P <0.05). With the increase of grade, the rates of high myopia increased ( χ 2 trend =674.56, 608.38, 655.21, 676.89, P <0.05), with junior grade 3 students being the most robust. The rate of high myopia in middle school students from 2019 to 2022 decreased from 15.09 to 14.22%, with an average annual rate of 2.08% ( APC=-2.08, t=-7.99, P ＜0.05). The refractive error of high myopia middle school students in 2019 and 2022 were -7.44(-10.25, -6.00) and -7.38(-10.00, -6.00)D, respectively, with no statistically significant difference ( H=4.30, P >0.05). Conclusions The rate of high myopia in middle school students in Beijing shows a decreasing trend, but it remains at a high level. It is necessary to classify the prevention and control strategy, and standardize the measures in order to manage early onset, high incidence rates, and severe myopia.

Objective: To analyze the current status and related factors of comorbidity of myopia, obesity, and depression symptoms among middle school students in Beijing, so as to provide a basis for comprehensive public health interventions for common diseases. Methods: Through stratified cluster random sampling in October 2022, a total of 11 262 junior high school, senior high school, and vocational high school students in 16 districts of Beijing were surveyed with self administered questionnaires, physical examinations and visual acuity examinations. The χ 2 test and binary Logistic regression model were used to analyze group differences in the comorbidity of myopia, obesity and depression symptoms and factors influencing the comorbidity. Stratified analysis was applied to analyze the associations between health risk behaviors and the comorbidity. Results: The detection rate of comorbidity of myopia, obesity, and depression symptoms among middle school students in Beijing was 3.35%, the comorbidity rate among vocational high school students (4.61%) was higher than that in junior high school students (2.80%) and senior high school students (3.41%). The comorbidity rate was higher among students in suburban areas (3.66%) than that in urban areas (2.92%), and the differences was statistically significant ( χ 2=15.02, 4.63, P <0.05). Binary Logistic regression analyses indicated that middle school students with poor dietary behaviors ( OR =1.59) and excessive screen time ( OR =1.70) were associated with elevated risk of comorbidity of myopia, obesity, and depression symptoms. Both boys and girls with poor dietary behaviors ( OR =1.63, 1.69) and excessive screen time ( OR =1.45, 2.23) had elevated likelihood of comorbidity of myopia, obesity and depression symptoms. Students in junior high school and senior high school with poor dietary behaviors ( OR =2.16, 1.47) and excessive screen time ( OR =2.20, 1.63 ) had elevated likelihood of comorbidity of myopia, obesity, and depression symptoms ( P <0.05). Conclusions The current status of comorbidity of myopia, obesity, and depression symptoms among middle school students in Beijing is concerning. Schools and parents should work together to guide students to develop healthy behaviors such as balanced diet and moderate video, in order to achieve the goal of controlling myopia, obesity and depression symptoms.