Associations of recent stressful life events with anxiety symptoms among Chinese adolescents with a consideration of family functioning.

Background: The association between stressful life events (SLEs) and adolescent anxiety symptoms has been extensively studied, but the specific impacts of different SLEs domains remain inconclusive. Moreover, limited research has examined the role of family functioning in these associations.Objective: This study aimed to investigate the associations between various recent SLEs and adolescent anxiety symptoms and explore the role of family functioning.Methods: Data were obtained from the second phase of the Longitudinal Study of Adolescents' Mental and Behavioral Well-being Research in Guangzhou, China. A total of 10,985 students (51.9% boys; mean [SD] age, 15.3 [1.5] years) from forty middle schools participated in the study in 2022 and completed a self-report questionnaire assessing anxiety symptoms, SLEs, and family functioning using the Generalized Anxiety Disorder-7 (GAD-7), Adolescent Self-rating Life Events Checklist (ASLEC; including five subscales: interpersonal stress, academic stress, punishment-related stress, loss-related stress, and adaptation-related stress), and the adapted Chinese version of the Family Assessment Device (FAD), respectively. Linear mixed-effects models were performed and the moderation role of family functioning was also examined.Results: The fully adjusted model revealed that a 1-SD increase in the overall ASLEC score was associated with higher levels of anxiety symptoms (ß = 2.23, 95%CI: 2.15-2.32). Among various SLEs domains, the academic domain shows the most significant association (ß = 2.25, 95%CI: 2.17-2.33). Family functioning exerted an independent protective influence on anxiety symptoms, with each 1-SD increase in FAD scores negatively associated with anxiety symptoms (ß = -2.11, 95%CI: - 2.29 to - 1.93) in the adjusted model. Moreover, family functioning significantly buffered the impacts of overall SLEs and each domain, except for adaptation-related SLEs, on anxiety symptoms.Conclusion: Higher recent SLEs levels were associated with increased anxiety symptoms among adolescents, with academic SLEs showing the greatest association. Positive family functioning had both direct and buffering influences on anxiety symptoms.

Higher levels of recent stressful life events may increase adolescents' anxiety symptoms.Academic stressful life events show the greatest association with anxiety symptoms.Family functioning may be a promising intervention target for adolescent anxiety symptoms.

Effects of online family health education on myopia prevention in children by parental myopia: a randomized clinical trial.

CLINICAL RELEVANCE: Online family health education may be effective for myopia prevention in children, and the effects may be different between children with myopic and non-myopic parents. BACKGROUND: Myopia is a common cause of vision loss. The aims of this study were to evaluate the effects of online family health education on preventing the development of myopia in children, and to estimate whether the effects vary according to parental myopia. METHODS: A cluster randomised trial including grade 1 and grade 2 children from 12 primary schools was conducted in Guangzhou, China. Weekly online family health education messages were sent to parents in the intervention group. Data collection included eye examinations of children and questionnaires completed by parents. RESULTS: Among the 3123 children included at baseline (1703 boys [54.5%]; mean [SD] age, 6.83 [0.73] years), 2376 completed the follow-up after 3 years. The differences in the incidence of myopia and myopic shift between the study groups were not significant in total. However, the 3-year cumulative incidence rate of myopia in the intervention group (125 of 445 [28.1%]) was significantly lower than that in the control group (225 of 603 [37.3%]; difference, 9.2% [95% CI, -14.9% to -3.5%]; P = 0.001) among children with non-myopic parents. In parallel, among children with non-myopic parents, the mean myopic change in SER was less for the intervention group than for the control group (-1.10 D vs. -1.24 D; difference, 0.13 D [95% CI, 0.03 to 0.23 D]; P = 0.01). CONCLUSIONS: Compared with children with myopic parents, online family health education was more effective in children with non-myopic parents. The incidence of myopia and myopic shift in refraction have been reduced in children with non-myopic parents. Further studies are needed to assess these differences by parental myopia.

Associations of family functioning and parental styles with anxiety symptoms among high grade primary school students / 中国学校卫生

Objective@#To investigate the prevalence of anxiety symptoms among high grade primary school students in Guangzhou and their correlation with family functioning and parental parenting styles, so as to provide theoretical basis and guidance for family based interventions for children s anxiety symptoms.@*Methods@#From June to September 2022, a multi stage cluster random sampling method was employed to select 5 396 students from grades 4 to 6 in 13 primary schools in Guangzhou. The Family Functioning Assessment Scale for Children, Parental Bonding Instrument, and Spence Children s Anxiety Scale Short Version were used for the survey. Inter group comparison was analysed by t test or analysis of variance. Linear regression analysis was used to explore the effects of family function and parental parenting styles on anxiety symptoms in primary school students.@*Results@#The average score for anxiety symptoms among high grade primary school students in Guangzhou was (11.63±10.88). In terms of parenting styles, mothers scored higher than fathers in the dimensions of "care" (25.63±4.92) and "control" (5.08±2.58) compared to fathers ( 24.74± 5.50, 5.00±2.51) ( t =15.80, 4.21, P <0.01). However, there was no statistically significant difference in the scores of parents on the dimension of "encouragement of independence"（12.98±4.06,13.05±3.95)( t =-1.77， P >0.05）. After adjusting for general demographic characteristics, the results of linear regression analysis showed that primary school students family functioning ( B =0.47) and parental "control" ( B =0.67, 0.75) were positively associated with anxiety symptoms scores ( P <0.01). Meanwhile, parental "care" ( B =-0.53,-0.55) and "encouragement of independence" ( B =-0.62,-0.68) were negatively associated with anxiety symptom scores ( P <0.01). These associations remained statistically significant even after further adjusting for family functioning ( P <0.01).@*Conclusions@#Family functioning, parenting styles are closely associated with anxiety symptoms among high grade primary school students. Positive family functioning and parenting styles may mitigate childhood anxiety symptoms, whereas excessive parental control may increase the risk of childhood anxiety symptoms.

Trajectories of spherical equivalent refraction from grades 1 to 4 in Chinese children.

BACKGROUND: The development trajectories of children's SER remain unknown. This study aimed to characterize spherical equivalent refraction (SER) trajectories during grades 1-4 in Chinese children. METHODS: This prospective cohort study included 1226 first-grade non-myopic children from 12 public primary schools, randomly selected in two districts in Guangzhou, China. From November 2018 to March 2022, four-wave ocular examinations and questionnaire surveys have been completed. The group-based trajectory modeling was used to explore SER trajectories in grades 1-4. RESULTS: All five trajectories showed an upward trend and rose faster after grade 2. Children in the sharp-developing (n = 44), high-developing (n = 136), and rapid-developing (n = 237) myopia groups developed myopia before grades 2, 3, and 4, respectively. Their SER development speed remained at a relatively high level after myopia, almost consistent with that before myopia. Children in the moderate-developing (n = 418) and low-developing (n = 391) non-myopia groups did not develop myopia before grade 4. Some characteristics in grade 1 were independently associated with SER trajectories, including sex, axial length, number of parents with myopia, residence, academic achievement, and the duration of outdoor activity. Based on the baseline characteristics, we established the model predicting the probability of children belonging to each group. CONCLUSIONS: Myopia interventions are best started in grade 1 or preschool age. If interventions are not taken in time, the latest intervention window might be in grades 1, 2, and 3 for children with a high probability of belonging to the sharp-developing, high-developing, and rapid-developing myopia groups, respectively. The above probabilities might be predicted using the model we established. Moreover, the interventions for myopic children shouldn't be ignored.

Transmission of Mycobacterium tuberculosis in schools: a molecular epidemiological study using whole-genome sequencing in Guangzhou, China.

Background: China is a country with a high burden of tuberculosis (TB). TB outbreaks are frequent in schools. Thus, understanding the transmission patterns is crucial for controlling TB. Method: In this genomic epidemiological study, the conventional epidemiological survey data combined with whole-genome sequencing was used to assess the genotypic distribution and transmission characteristics of Mycobacterium tuberculosis strains isolated from patients with TB attending schools during 2015 to 2019 in Guangzhou, China. Result: The TB incidence was mainly concentrated in regular secondary schools and technical and vocational schools. The incidence of drug resistance among the students was 16.30% (22/135). The phylogenetic tree showed that 79.26% (107/135) and 20.74% (28/135) of the strains belonged to lineage 2 (Beijing genotype) and lineage 4 (Euro-American genotype), respectively. Among the 135 isolates, five clusters with genomic distance within 12 single nucleotide polymorphisms were identified; these clusters included 10 strains, accounting for an overall clustering rate of 7.4% (10/135), which showed a much lower transmission index. The distance between the home or school address and the interval time of symptom onset or diagnosis indicated that campus dissemination and community dissemination may be existed both, and community dissemination is the main. Conclusion and recommendation: TB cases in Guangzhou schools were mainly disseminated and predominantly originated from community transmission. Accordingly, surveillance needs to be strengthened to stop the spread of TB in schools.

Association between academic pressure, NR3C1 gene methylation, and anxiety symptoms among Chinese adolescents: a nested case-control study.

BACKGROUND: Academic pressure is a prevalent stressor among Chinese adolescents and is often linked to anxiety symptoms, although the underlying mechanism remains unclear. This study aimed to investigate the association between NR3C1 gene methylation, academic pressure, and anxiety symptoms among Chinese adolescents. METHODS: This nested-case control study included 150 adolescents (boys: 38.7%; baseline age: 12-17 years) from a school-based longitudinal study of Chinese adolescents. Cases (n = 50) were defined as those with anxiety symptoms at both baseline and follow-up, while controls (n = 100) were randomly selected from those without anxiety symptoms at both timepoints. The cases and controls were 1:2 matched by age. Academic pressure, anxiety symptoms, and potential covariates were measured using a self-report questionnaire. Peripheral whole blood samples were collected from each participant for the detection of cortisol level (i.e., morning serum cortisol level) and DNA methylation. The methylation analysis included a total of 27 CpG units at the NR3C1 promoter region. RESULTS: The final adjusted models showed that students with heavy academic pressure at baseline were at a higher risk of anxiety symptoms at follow-up compared to those with mild academic pressure (ß estimate: 6.24 [95% CI: 3.48 ~ 9.01]). After adjusting for covariates, the methylation level of one CpG unit (NR3C1-16 CpG10) in NR3C1 differed significantly between cases and controls (F = 6.188, P = 0.014), and the difference remained significant after correction for multiple testing (P < 0.025). The adjusted regression models showed that moderate (ß estimate = 0.010 [95% CI: 0.000 ~ 0.020], P = 0.046) and heavy (ß estimate = 0.011 [95% CI: 0.001 ~ 0.020], P = 0.030) academic pressure were significantly associated with the methylation level of NR3C1-16 CpG 10. Further mediation analysis demonstrated that the association of academic pressure and anxiety symptoms was significantly mediated by the methylation of NR3C1-16 CpG 10 (ß estimate for indirect effect = 0.11 [95% CI: 0.005 ~ 0.32]; indirect/total effect = 8.3%). CONCLUSION: The present study suggests that NR3C1-16 CpG 10 DNA methylation might be a potential mechanism that partially explains the lasting effects of academic pressure on subsequent anxiety symptoms among adolescents. Further studies with larger sample sizes are recommended to replicate this finding.

The Causal Effect of Education on Myopia: Evidence That More Exposure to Schooling, Rather Than Increased Age, Causes the Onset of Myopia.

Purpose: To distinguish the effects of age and grade on the development of myopia. Methods: Grade 1 (n = 1465, mean age 6.71 ± 0.29 years; 53.5% male) and Grade 2 students (n = 1381, mean age 7.76 ± 0.30 years; 52.5% male) were examined in 2018, with a follow-up examination in 2019. Cycloplegic spherical equivalent (SE) in diopter (D) was measured. Regression discontinuity (RD) analysis was used to assess the causal effects on refraction at each visit. Results: The sample in a grade was divided into three 4-month age blocks according to their birth month, the youngest, middle, and the oldest. At the 2018 visit, within each grade, there were no significant differences in SE among age blocks (all P > 0.05), despite an age range of 12 months. However, comparing the youngest block in Grade 2 to the oldest block in Grade 1, an average age difference of four months, a significant difference in SE was found (0.82 ± 0.69 D vs. 1.05 ± 0.55 D, t-test P < 0.01). Formal RD analysis found a significant casual effect of grade increase on myopic refraction shift (ß = -0.32 D; 95% CI, -0.73 to -0.01; P = 0.042). Consistent results were found using the 2019 data. Conclusions: Increased grade, rather than increasing age, is the major cause of myopic shifts in refraction. A causal link implies that interventions aimed at reducing the myopigenic exposures experienced during a school year have the potential to markedly reduce the myopic shifts in refraction associated with a grade of schooling.

Reciprocal relationships between self-esteem, coping styles and anxiety symptoms among adolescents: between-person and within-person effects.

BACKGROUND: Previous researches have not distinguished the between-person effects from the within-person effects when exploring the relationship between self-esteem, coping styles, and anxiety symptoms among adolescents. To address this gap, this study investigated reciprocal associations among self-esteem, coping styles, and anxiety symptoms in a three-wave longitudinal panel survey, using an analytical strategy that disaggregates the within-person and the between-person variance. METHODS: Data was drawn from the Longitudinal Study of Adolescents' Mental and Behavioral Well-being Research study conducted in 10 public schools in the Guangdong province of China. All participants had a baseline visit (N = 1957, mean age 13.6, grades 7 and 10) and follow-up interviews at 1-year intervals for 3 years. A random intercept cross-lagged panel model combined with mediation analysis was performed. RESULTS: At the within-person level, the following results were observed. (1) Low self-esteem and anxiety symptoms bidirectionally predicted each other. (2) Low self-esteem and negative coping style bidirectionally predicted each other. (3) Anxiety symptoms predicted subsequent negative coping style but not vice versa. At the between-person level, we obtained the following main results. (1) Significant predictive effects on the random intercept were found among all three study constructs. (2) There were sex differences regarding the association between self-esteem and anxiety symptoms and the correlation of females was stronger than that of males. (3) Self-esteem mediated the reciprocal relations between coping styles and anxiety symptoms. CONCLUSIONS: Overall, findings revealed a reciprocal relationship between low self-esteem and anxiety symptoms for both females and males. Besides, anxiety symptoms predict subsequent negative coping style but not vice versa. We also highlighted the mediating role of self-esteem in the reciprocal relations between coping styles and anxiety symptoms. Thus, interventions targeted at promoting self-esteem and cultivating positive coping style may help reduce adolescent anxiety.

Axial Growth Driven by Physical Development and Myopia among Children: A Two Year Cohort Study.

Background: The physical process of axial length growth among children and its role in the occurrence of myopia remain insufficiently explored. In this study, we investigate the patterns of ocular axial growth among persistent myopia (PM) and persistent non-myopia (PNM) children aged 3 to 15 years. Methods: A group of 6353 children aged 3 to 15 years, selected from rural schools in China, were followed up annually for 2 years. Biometric measurements including axial length (AL) and spherical equivalent refraction (SER) were obtained. Body height was recorded. Children were divided into two groups: PM group defined as SER of −0.50 D or less; PNM group defined as −0.50 D < SER < +3.0 D during follow-up. Results: Annual AL growth was fairly consistent for PNM eyes of children aged 3 to 11 years and then reduced significantly (independent t test, p < 0.001) for children aged 12 years and older. This pattern of AL changes was similar for PM children, although the AL growth was greater among them. Among children aged 6 and older, body height change was concomitant to AL growth (p < 0.01) and SER myopic shift (p < 0.001) until reaching 12 years old (p = 0.308 and p = 0.679, respectively). Conclusions: Stature growth and AL growth are both remarkable and consistent and concomitant but start to attenuate when the children reach 10 to 12 years old among emmetropic children. This observation suggests that AL growth is driven by physical development until 12 years old, whereas its excessive growth is dominated by myopia development.

Association Between Childhood Maltreatment, FKBP5 Gene Methylation, and Anxiety Symptoms Among Chinese Adolescents: A Nested Case-Control Study.

BACKGROUND: Anxiety symptoms are common mental health problems among adolescents worldwide. This study aimed to explore (1) the longitudinal association between childhood maltreatment and anxiety symptoms, (2) the association between childhood maltreatment and DNA methylation of the FKBP5 gene, and (3) the association of DNA methylation of the FKBP5 gene with anxiety symptoms at follow-up. METHODS: A nested case-control design was conducted to identify a case group and control group from a longitudinal study of adolescents aged 13-18 years in Guangzhou from 2019 to 2020. Adolescents with anxiety symptoms at baseline and follow-up were considered the case group, while those without anxiety symptoms at baseline and follow-up were considered the control group. The case and control groups were matched according to age and sex. Our study finally included 97 cases and 141 controls. RESULTS: After adjusting for significant covariates, childhood emotional abuse was associated with subsequent anxiety symptoms (ß = 0.146, 95% CI = 0.010~0.283); students with physical and emotional neglect were more likely to get a lower level of DNA methylation at most CpG units of FKBP5 gene (P < 0.05); FKBP5-12 CpG 15 methylation was associated with anxiety symptoms at follow-up (ß = -0.263, 95% CI = -0.458~-0.069). However, after multiple hypothesis testing, childhood maltreatment was not associated with FKBP5 DNA methylation (q > 0.10); FKBP5 DNA methylation did not show an association with subsequent anxiety symptoms (q > 0.10). CONCLUSIONS: Childhood emotional abuse was associated with an increased risk of anxiety symptoms among Chinese adolescents. After multiple hypothesis testing, childhood maltreatment was not significantly associated with FKBP5 DNA methylation. DNA methylation of the promoter region of the FKBP5 gene was not a significant predictor of anxiety symptoms. More attention should be paid to the mental health of adolescents with childhood maltreatment.

Associations of FKBP5 polymorphisms and methylation and parenting style with depressive symptoms among Chinese adolescents.

BACKGROUND: Genetic factors may interplay with environmental stressors to contribute to risks of depressive symptoms. This study aimed to investigate the association of FKBP5 polymorphisms and DNA methylation with depressive symptoms among Chinese adolescents, considering the role of parenting style. METHODS: This study used a nested case-control study design based on a cohort study, and the case (n = 120) and control groups (n = 118) were matched with age. Depressive symptoms, parenting style, and other demographics were measured. Fourteen potential polymorphisms and one promoter region in the FKBP5 gene were selected for genotyping and methylation analysis. RESULTS: In the adjusted models, a significant association between FKBP5 rs7757037 and depressive symptoms was found in the codominant model (AG vs. GG; adjusted odds ratio [AOR] = 2.56, 95% CI = 1.13-5.78) and dominant model (AA+AG vs. GG; AOR = 2.38, 95% CI = 1.11-5.120); rs2817032 and rs2817035 polymorphisms were associated with depressive symptoms in the codominant model and dominant model. Significant interactions between rs7757037 and the father's parenting style were found in the codominant model (P = 0.043) and dominant model (P = 0.043), but the gene-environment interactions were not significant after correcting for multiple testing. Moreover, the significant main effects of FKBP5 methylation status on depressive symptoms were not observed, and there was no significant interaction between FKBP5 methylation status and parenting style on depressive symptoms. CONCLUSIONS: Further studies are required to confirm the effect of FKBP5 polymorphisms and methylation as well as their interactions with parenting styles in larger samples.

Rates of Myopia Development in Young Chinese Schoolchildren During the Outbreak of COVID-19.

Importance: During the outbreak of COVID-19, outdoor activities were limited and digital learning increased. Concerns have arisen regarding the impact of these environmental changes on the development of myopia. Objective: To investigate changes in the development of myopia in young Chinese schoolchildren during the outbreak of COVID-19. Design, Setting, and Participants: In this observational study, 2 groups of students from 12 primary schools in Guangzhou, China, were prospectively enrolled and monitored from grade 2 to grade 3. Comparisons between the exposure and nonexposure groups were made to evaluate any association between environmental changes during the COVID-19 outbreak period and development of myopia. The exposure group received complete eye examinations in November and December 2019 and November and December 2020. The nonexposure group received examinations in November and December 2018 and November and December 2019. Main Outcomes and Measures: Changes in cycloplegic spherical equivalent refraction (SER), axial length (AL) elongation, and myopia incidence from grade 2 to grade 3. Results: Among the 2679 eligible students in grade 2 (mean [SD] age, 7.76 [0.32] years; 1422 [53.1%] male), 2114 (1060 in the nonexposure group and 1054 in the exposure group) were reexamined in grade 3. Compared with the period from November and December 2018 to November and December 2019, the shift of SER, AL elongation, and myopia incidence from grade 2 to grade 3 from November and December 2019 to November and December 2020 was 0.36 D greater (95% CI, 0.32-0.41; P < .001), 0.08 mm faster (95% CI, 0.06-0.10; P < .001), and 7.9% higher (95% CI, 5.1%-10.6%; P < .001), respectively. In grade 3 students, the prevalence of myopia increased from 13.3% (141 of 1060 students) in November and December 2019 to 20.8% (219 of 1054 students) in November and December 2020 (difference [95% CI], 7.5% [4.3-10.7]; P < .001); the proportion of children without myopia and with SER greater than -0.50 D and less than or equal to +0.50 D increased from 31.1% (286 of 919 students) to 49.0% (409 of 835 students) (difference [95% CI], 17.9% [13.3-22.4]; P < .001). Conclusions and Relevance: In this study, development of myopia increased during the COVID-19 outbreak period in young schoolchildren in China. Consequently, myopia prevalence and the proportion of children without myopia who were at risk of developing myopia increased. Future studies are needed to investigate long-term changes in myopia development after the COVID-19 pandemic.

Effect of School-Based Family Health Education via Social Media on Children's Myopia and Parents' Awareness: A Randomized Clinical Trial.

Importance: Myopia is a common cause of vision loss, and its prevalence is increasing globally. Objective: To evaluate the effects of school-based family health education via WeChat in raising parents' awareness of myopia prevention and behavior and in controlling the development of myopia in children. Design, Setting, and Participants: A single-masked cluster randomized clinical trial of children was conducted from October 1, 2018, to December 31, 2020, among grade 1 students from 12 primary schools in Guangzhou, China. The 12 primary schools were randomly selected in 2 districts and randomized to the intervention and control groups. All grade 1 students were invited to participate, and 688 students were included in the intervention group and 752 in the control group. Interventions: Weekly health education via the social media platform WeChat was provided to the parents in the intervention group. Main Outcomes and Measures: Data include results of eye examinations of children and questionnaires completed by parents. The primary outcome was the 2-year cumulative incidence rate of myopia. Myopia was defined as a spherical equivalent (SE) refractive error (sphere of +0.5 cylinder) of at least -0.50 diopters (D). The secondary outcomes were the 2-year changes in the axis length and SE refraction, parental awareness, children's screen time, outdoor activities, and learning tools during COVID-19. Results: Among the 1525 children included at baseline (835 boys [54.8%]; mean [SD] age, 6.3 [0.5] years), 1244 competed the final assessment; the 2-year cumulative incidence rate of myopia was 106 of 544 (19.5%) in the intervention group and 171 of 700 (24.4%) in the control group (difference, 4.9% [95% CI, 0.3%-9.5%]; P = .04). The mean myopic shift in SE refraction in the intervention group (-0.82 D) was lower than that in the control group (-0.96 D; difference, -0.14 [95% CI, -0.22 to -0.06] D; P < .001). No difference in change in axial length was detected (difference, 0.02 [95% CI, -0.06 to 0.09] mm; P = .70). Conclusions and Relevance: School-based weekly family health education via WeChat resulted in a small decrease in the 2-year cumulative incidence rate of myopia with a difference in SE of less than 0.25 D not accompanied by any axial length differences. Whether these findings extrapolate elsewhere in the world or are clinically relevant in the short or long term remain to be determined. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR1900022236.

The Correlation between Chinese Written Vocabulary Size and Cognitive, Emotional and Behavioral Factors in Primary School Students.

Written vocabulary size plays a key role in children's reading development. We aim to study the relationship between Chinese written vocabulary size and cognitive, emotional, and behavioral factors in primary school students. Using stratified cluster sampling, 1162 pupils from Grade 2~5 in Guangzhou were investigated. Chinese written vocabulary size, cognitive, emotional, and behavioral factors were assessed by the Chinese written vocabulary size assessment scale, the dyslexia checklist for Chinese children (DCCC) and the Strengths and Difficulties Questionnaire (SDQ), respectively. The scores of visual word recognition deficit (ß = -3.32, 95% CI: -5.98, -0.66) and meaning comprehension deficit (ß = -6.52, 95% CI: -9.39, -3.64) were negatively associated with Chinese written vocabulary size; the score of visual word recognition deficit (odds ratio (OR) = 1.04, 95% CI: 1.02, 1.07) was the related factor of a delay in written vocabulary size. The score of meaning comprehension deficit was negatively associated with boys' Chinese written vocabulary size, while the score of auditory word recognition deficit was negatively associated with girls' Chinese written vocabulary size. The related factor of a delay in written vocabulary size was spelling deficit in boys and visual word recognition deficit in girls. There is a significant correlation between Chinese written vocabulary size and cognitive factors, but not emotional and behavioral factors in primary school students and these correlations are different when considering gender.

Associations of emotional and behavioral problems with Internet use among Chinese young adults: the role of academic performance.

BACKGROUND: To investigate the independent association between different types of emotional and behavioral problems and Internet use (i.e., Internet use time and problematic Internet use [PIU]) among Chinese young adults, and to test whether these associations vary by academic performance. METHODS: Data was drawn from the 2019 National School-based Chinese Adolescents Health Survey, and 30,581 undergraduates (mean age: 19.9 [SD: 1.6] years) completed standard questionnaires qualifiedly. Daily hours of Internet use, PIU, emotional and behavioral problems, and academic performance were measured. RESULTS: After adjusting for control variables and academic performance, students who reported having emotional problems (daily hours: adjusted unstandardized ß estimate=0.14, 95% CI=0.12~0.15; PIU: adjusted unstandardized ß estimate=1.82, 95% CI=1.77~1.89), conduct problems (daily hours: adjusted unstandardized ß estimate=0.12, 95% CI=0.09~0.15; PIU: adjusted unstandardized ß estimate=1.76, 95% CI=1.67~1.84), hyperactivity (daily hours: adjusted unstandardized ß estimate=0.08, 95% CI=0.06~0.12; PIU: adjusted unstandardized ß estimate=1.46, 95% CI=1.38~1.54), and peer problems (daily hours: adjusted unstandardized ß estimate=0.03, 95% CI=0.002~0.05; PIU: adjusted unstandardized ß estimate=0.53, 95% CI=0.44~0.62) were more likely to engaged in prolonged daily Internet use and PIU. In contrast, prosocial behavior was negatively associated with Internet use time and PIU. Stratified analyses showed that some of the associations in poor academic performers were stronger than in students with good and average academic performance. LIMITATIONS: The cross-sectional design limited the ability to make causal inferences. CONCLUSIONS: The findings suggest that the efforts to prevent abnormal Internet use should be focused on students with emotional and behavioral problems or poor academic performance.

The associations between sleep situations and mental health among Chinese adolescents: A longitudinal study.

OBJECTIVE: Few studies are conducted to explore the longitudinal relationships between sleep situations and mental health among adolecents. This study aimed to explore the sleep situations (ie, sleep habits and sleep problems) among Chinese adolescents and the longitudinal associations between sleep situations and mental disorder symptoms (ie, depressive and anxiety symptoms). METHODS: This longitudinal study included 1957 high school students from ten schools in Guangzhou in January 2019, with 1836 students contributing valid data at a one-year follow-up (retention rate: 93.9%). Data of depressive and anxiety symptoms, sleep habits, and sleep problems were collected using a self-reported questionnaire. RESULTS: The current study found that over half of the adolescents did not reach the recommended 8-h sleep-time on weekdays (63.3%). Short sleep duration, especially on weekdays, was significantly associated with subsequent depressive (AOR = 0.86, 95%CI: 0.80-0.92) and anxiety symptoms (AOR = 0.86, 95%CI: 0.77-0.96). In addition, longer weekday-weekend catch-up sleep and more sleep problems were risk factors of depressive and anxiety symptoms. CONCLUSIONS: The health effects of insufficient sleep and suboptimal sleep quality on adolescents should not be neglected. Our longitudinal research showed that adolescents would demonstrate severer depressive and anxiety symptoms if lacking of a healthy sleeping practice. A regular sleep schedule and close attention to adolescents' mental disorders are highly recommended.

Physical activity, screen exposure and sleep among students during the pandemic of COVID-19.

This study aimed to determine the levels of health-related behaviours (physical activity, screen exposure and sleep status) among Chinese students from primary, secondary and high schools during the pandemic of COVID-19, as well as their changes compared with their status before the pandemic. A cross-sectional online survey of 10,933 students was conducted among 10 schools in Guangzhou, China, between 8th and 15th March, 2020. After getting the informed consent from student's caregivers, an online questionnaire was designed and used to obtain time spending on health-related behaviours during the pandemic of COVID-19, as well as the changes compared with 3 months before the pandemic, which was completed by students themselves or their caregivers. Students were stratified by regions (urban, suburban, exurban), gender (boys and girls), and grades (lower grades of primary school, higher grades of primary schools, secondary schools and high schools). Data were expressed as number and percentages and Chi-square test was used to analyse difference between groups. Overall, the response rate of questionnaire was 95.3% (10,416/10,933). The median age of included students was 13.0 (10.0, 16.0) years and 50.1% (n = 5,219) were boys. 41.4%, 53.6% and 53.7% of total students reported less than 15 min per day in light, moderate and vigorous activities and 58.7% (n = 6,113) reported decreased participation in physical activity compared with the time before pandemic. Over 5 h of screen time spending on online study was reported by 44.6% (n = 4,649) of respondents, particular among high school students (81.0%). 76.9% of students reported increased screen time compared with the time before pandemic. Inadequate sleep was identified among 38.5% of students and the proportion was highest in high school students (56.9%). Our study indicated that, during the COVID-19 pandemic, the school closure exerted tremendous negative effects on school-aged children's health habits, including less physical activity, longer screen exposure and irregular sleeping pattern.

Association between problematic internet use and behavioral/emotional problems among Chinese adolescents: the mediating role of sleep disorders.

BACKGROUND: Studies that focus on the relationships of problematic Internet use (PIU), sleep disorders, and behavioral/emotional problems were limited. This study aimed to explore (1) the relationship between PIU and behavioral/emotional problems among Chinese adolescents and (2) whether sleep disorders mediate the relationship between PIU and behavioral/emotional problems. METHODS: A total of 1,976 adolescents were recruited by cluster sampling from ten secondary schools in Guangzhou between January and April 2019, and 1,956 of them provided valid information (response rate: 98.9% ). Among them, 50.8% were males and the mean age was 13.6±1.5 years, ranging from 11 to 18 years. Data on behavioral/emotional problems, sleep disorders, and PIU were collected using a self-reported questionnaire. Linear regression models and mediation analyses were performed. RESULTS: Of the participants, 14.5% (284/1,956) reported moderate to severe PIU, and their average score for total difficulties was significantly higher than the score for average users (14.9±5.5 Vs 9.8±4.7). After adjusting for controlled variables, PIU was further proven to be positively related to elevated levels of behavioral/emotional problems (unstandardized ß = 0.16, p < 0.05). In addition, sleep disorders partially mediated the forgoing associations. CONCLUSIONS: Adolescents with problematic Internet habits were at higher risk of developing behavioral and emotional problems than their normal-use peers, and sleep disorders partially mediated the effect. Close attention and effective guidance for adolescents with PIU and behavioral/emotional problems were recommended for parents and schools.

Associations Among Screen Time, Sleep Duration and Depressive Symptoms Among Chinese Adolescents.

OBJECTIVES: Relatively few studies have explored the inter-relationship between screen time (ST), sleep duration and depressive symptoms. The study herein sought to determine (1) the relationships between ST, sleep duration and depressive symptoms among Chinese adolescents; (2) whether sleep duration mediates the relationships between ST and depressive symptoms. METHODS: 1st grade students (n=1,976) from ten high schools in Guangzhou, China were invited through cluster sampling between January and April 2019. Self-reported ST with electronic devices and Internet, sleep duration, and The Center for Epidemiology Scale for Depression (CES-D) score were collected. Generalized mixed linear models and mediation analyses were conducted. RESULTS: There were 1,956 self-reported questionnaires received (response rate: 98.99%). Approximately 25% (471/1,929 for Internet use, 399/1,928 for electronic device) of the total sample reported ST >2 hours/day. Approximately 8.9% (169/1,894) reported a CES-D score >28. Longer ST with electronic devices (estimate=0.52, 95%CI: 0.24~0.80), Internet usage (estimate=0.82, 95%CI: 0.53~1.11) were positively associated with depressive symptoms, while less sleep (estimate=-1.85, 95%CI: -2.27~-1.43) was negatively associated with depressive symptoms. There is significant indirect effect of electronic device usage on depressive symptoms through sleep duration (indirect effect=0.08, 95%CI: 0.01~0.15). LIMITATIONS: This study only included school students from Guangzhou. Causal relationship cannot be inferred by this cross-sectional design. CONCLUSIONS: ST and sleep duration were significantly associated with depressive symptoms severity. The indirect effect of sleep duration suggests a possible mechanism of the association between ST and depressive symptoms. Future interventions to manage depressive symptoms should target sleep time and decrease ST among adolescents.

Associations Between Poor Sleep Quality, Anxiety Symptoms, and Depressive Symptoms Among Chinese Adolescents Before and During COVID-19: A Longitudinal Study.

Since the novel coronavirus disease 2019 (COVID-19) outbreak, adolescents' emerging mental health and behavior issues have been an international public health concern. This longitudinal study aimed to examine the situation of poor sleep quality, anxiety, and depressive symptoms among Chinese adolescents and to explore the associations between them before and during COVID-19. A total of 1,952 middle and high school students as eligible participants at baseline (pre-COVID-19, Wave 1; response rate: 98.79%), 1,831 eligible students were followed up at Wave 2 (October 2019 to December 2019, pre-COVID-19; retention rate: 93.80%), and 1,790 completed the follow-up at Wave 3 (during the COVID-19; retention rate: 97.80%). The mean age of the baseline students was 13.56 (SD: 1.46) years. The differences in anxiety and depressive symptoms between Wave 1, Wave 2, and Wave 3 were not statistically significant. The proportion of students with poor sleep quality increased over time, from Wave 1 (21.0%) to Wave 3 (26.0%, OR = 1.37, 95% CI = 1.17-1.60, P = 0.001) and from Wave 2 (21.9%) to Wave 3 (OR = 1.29, 95% CI = 1.11-1.51, P < 0.001). The cross-lagged generalized linear mixed models revealed that the concurrent and cross-lagged associations of poor sleep quality with anxiety symptoms across the three waves were significant (P < 0.05) and vice versa. Only a marginally significant positive cross-lagged association between poor sleep quality at Wave 2 and depressive symptoms at Wave 3 was found (standardized ß estimate = 0.044, SE = 0.022, P = 0.045). Sleep quality was adversely affected during COVID-19, and the bidirectional associations of poor sleep quality with anxiety symptoms could not be neglected.