Adolescent depression is a worldwide public health concern and has contributed to significant socioeconomic burden. Investigating the association between time spent on social media (TSSM) and depression may provide guidance toward the prevention and intervention of adolescent depression. However, related literature reported mixed findings in terms of the relationship between TSSM and depression in adolescents. Hence, we conducted a comprehensive dose–response meta-analysis to clarify this issue. We conducted a systematic title/abstract and topic search of the relative terms in Web of Science, PubMed, PsycINFO databases through 9 January 2022. Odd ratios (ORs) were used to examine the pooled effect size of the association between TSSM and risk of depression. Dose–response analysis was evaluated by a generalized least squares trend estimation. Twenty-one cross-sectional studies and five longitudinal studies including a total of 55,340 participants were included. Overall, more TSSM was significantly associated with a higher risk of depression symptoms (OR = 1.60, 95%CI: 1.45 to 1.75) with high heterogeneity (Q₍₂₉₎ = 105.9, p < 0.001; I² = 72.6%). The association was stronger for adolescent girls (OR = 1.72, 95%CI: 1.41 to 2.09) than boys (OR = 1.20, 95%CI: 1.05 to 1.37). Five studies with seven reports were included in dose–response analysis. There was a linear dose–response association of TSSM and risk of depression. The risk of depression increased by 13% (OR = 1.13, 95%CI: 1.09 to 1.17, p < 0.001) for each hour increase in social media use in adolescents. TSSM is associated with depression in a linear dose–response and gender-specific manner, which suggests the need for better monitoring of adolescent social media use. However, motivation, content, and engagement on and exposure to social media use may also be important contributing factors, making it necessary to interpret the current findings with caution. Therefore, further research is required to clarify not only the causal link between TSSM and depression by randomized control studies but also the influence of other factors, such as active vs. passive social media use or different types of engagement or environments in which social media is used.

Background and purpose: There are increasing concern about independent associations between physical activity, screen-based sedentary behavior (SSB), and psychological problems, but only a few studies have attempted to explore combined patterns of physical activity and SSB in adolescents and their correlations with psychological problems. This study was aimed at identifying combined patterns of moderate-to-vigorous physical activity (MVPA) and SSB and examining the prevalence of different combined patterns and their correlations with depression, anxiety, and self-injurious behavior among Chinese adolescents. Methods: Junior and senior high school students (N = 13,659; mean age 15.18±1.89) were recruited. Latent class analysis was conducted to identify combined patterns of MVPA and SSB. Associations between subgroups of MVPA and SSB and socio-demographic characteristics were assessed by logistic regression. Their correlation with depression, anxiety, and self-injurious behaviors was assessed by analysis of variance with analysis stratified by gender. Results: Four latent classes were identified: high MVPA/low SSB group (64.7%), low MVPA/low SSB (26.7%), low MVPA/high SSB (4.8%), and low MVPA/moderate SSB (3.9%). Generally, the high MVPA/low SSB class was a relatively healthy group. The low MVPA/high SSB class was at risk of enduring depression, anxiety, and self-injurious behavior, with boys being more at risk than girls. Conclusion: Four latent subgroups of MVPA and SSB were identified in Chinese adolescents. The findings highlight the potential role of concurrent MVPA and SSB, with gender-specific characteristics in the primary prevention of adolescent depression, anxiety, and self-injurious behaviors.

Background: The body of literature regarding the associations between physical activity and psychological problems lacks consensus. Moreover, the role of gender has been scarcely investigated. The present study sought to fill the gap in the data by examining the associations, if any, between moderate-to-vigorous physical activity (MVPA), psychological problems, and self-harm behaviors based on different biological genders (male–female). Methods: A self-administered questionnaire was used to measure MVPA and multiple psychological problems, including depression and anxiety; general emotion, behavior, and social problems; Attention Deficit Hyperactivity Disorder (ADHD); Oppositional Defiant Disorder (ODD); conduct problems; and self-harm behaviors. Participants were a nationally representative sample of Chinese high school students (N = 13, 349). A multiple logistic regression analysis of MVPA, stratified by gender, was conducted on the risk of psychological problems and self-harm behaviors in the total sample. Results: For boys, a high frequency of MVPA was associated with a lower risk of depression (OR = 0.68, 95% CI [0.57–0.81]) and anxiety (OR = 0.71, 95% CI [0.53–0.96]) compared to the reference group. The moderate frequency of MVPA was associated with a lower risk of ADHD (OR = 0.73, 95% CI [0.56–0.94]) compared to the reference group. For girls, both MVPA groups were associated with a lower risk of depression (moderate MVPA: OR = 0.81, 95% CI [0.70–0.94]; high MVPA: OR = 0.67, 95% CI [0.54–0.83]) compared to the reference group. High MVPA was associated with a lower risk of ADHD (OR = 0.58, 95% CI [0.37–0.89]) compared to the reference group. Only moderate frequency of MVPA was associated with a lower risk of ODD (OR = 0.79, 95% CI [0.64–0.97]). Conclusion: MVPA was associated with a lower risk of depression, anxiety, ADHD, and ODD in a gender-specific and MVPA frequency-specific manner. This implies that for specific psychological issues, PA interventions that are modified based on gender and frequency of MVPA may be more effective than PA interventions without these considerations.

Background: Research on the links between the behavioral inhibition and approach systems (BIS/BAS), and internet addiction (IA) in adolescents has been inconclusive. BIS/BAS may interact with adolescent trait characteristics, resulting in different outcomes. Grit may alter adolescents’ motivations, which can even be based on biological systems such as BIS/BAS. However, the impact of BIS/BAS and potential moderating factors on adolescents’ internet use remains unclear. This study aimed to examine the association between BIS/BAS and IA in adolescents and explore the potential moderating roles of the two facts of grit, passion and perseverance, on the association between BIS/BAS and IA. Methods: A total of 1,881 junior and senior high school students (M_age = 14.65, standard deviation _age = 1.81, ranging from 11 to 20 years) completed a self-reported measure of BIS/BAS, IA, and grit. Independent t-tests and chi-square tests were used to evaluate the differences between adolescents with IA and those with normal internet use. Pearson correlation and regression model analyses, including moderating model analysis, were used to qualify the associations between IA and BIS/BAS, as well as the potential moderating role of grit passion and perseverance. Results: The results showed that 19.1% of the participants met the criteria for IA. Both BIS (β = 0.085, t = 3.650, p < 0.001) and BAS (β = 0.06, t = 2.552, p < 0.05) were positively associated with IA risk, and grit-perseverance moderated the association between BIS and IA (β = − 0.230, bootstrap 95% confidence interval: − 0.450 to − 0.012) and BAS with IA (β = − 0.187, bootstrap 95% confidence interval: − 0.299 to − 0.076). Conclusion: These findings extend the current knowledge on the associations between BIS/BAS and IA. Moreover, the findings suggest that enhancing grit-perseverance may improve prevention and intervention of IA risk in adolescents who are sensitive to BIS and BAS.