Objective:To investigate the characteristics of Internet addiction(IA)in adolescents with depression and explore its relationship with impulsivity and aggressive personality traits.Methods:A total of 71 adolescent patients with depressive disorders were recruited from the Child Psychiatry Outpatient Clinic of Peking University Sixth Hospital between April 2021 and November 2022 (15 males, 56 females; median age 14 [13, 15] years) as the depressive disorder group. Additionally, 83 healthy adolescents (27 males, 56 females; median age 14 [13, 17] years) were recruited as the control group during the same period. Internet addiction was assed using the Chinese version of Young′s Internet Addiction Test (YIAT), with a total score≥50 indicating internet addiction. Impulsivity was evaluated using the Barratt Impulsiveness Scale-11(BIS-11), and aggression was measured with the Buss-Perry Aggression Questionnaire(BPAQ). Differences in internet addiction, impulsivity, and aggression between the depression group and the control group were analyzed. Pearson correlation analysis was used to explore the correlation between internet addiction and impulsivity, aggression. Hierarchical linear regression models were used to analyze the factors influencing internet addiction, and a parallel mediation model was used to examine the mediating effect of impulsivity and aggressive personality traits in the relationship between depressive disorders and internet addiction.Results:The prevalence of IA was significantly higher in adolescents with depression than the healthy control group [57.75%(41/71) vs 31.33%(26/83); χ 2=10.87, P<0.001]. Adolescents with depressive disorders also exhibited higher impulsivity (65.5±9.2 vs 57.0±9.2, t=-5.72, P<0.001) and aggression (56.3±16.0 vs 42.4±15.1, t=-5.13, P<0.001) compared to the control group. Internet addiction was positively correlated with aggression ( r=0.47, P<0.01) and impulsivity ( r=0.57, P<0.01). Hierarchical regression analysis with the YIAT total score as the dependent variable revealed that impulsivity ( β=0.48, P<0.001) and aggression ( β=0.24, P<0.001) significantly predicted internet addiction. Mediation analysis indicated that depressive disorders indirectly indirectly influenced internet addiction through parallel paths of impulsivity and aggression, with a total indirect effect of 0.543 (95% CI: 0.362-0.761). Conversely, internect addiction influenced depressive disorders through reverse parallel pathway of impulsivity and aggression with a total indirect effect of 0.038 (95% CI: 0.021-0.067). Direct effects were not significant in either direction. Conclusion:Adolescents with depressive disorders exhibit more internet addiction. Impulsivity and aggressive personality traits play bidirectional mediating roles in the relationship between depressive disorders and internet addiction.

Objective:To investigate the characteristics of Internet addiction(IA)in adolescents with depression and explore its relationship with impulsivity and aggressive personality traits.Methods:A total of 71 adolescent patients with depressive disorders were recruited from the Child Psychiatry Outpatient Clinic of Peking University Sixth Hospital between April 2021 and November 2022 (15 males, 56 females; median age 14 [13, 15] years) as the depressive disorder group. Additionally, 83 healthy adolescents (27 males, 56 females; median age 14 [13, 17] years) were recruited as the control group during the same period. Internet addiction was assed using the Chinese version of Young′s Internet Addiction Test (YIAT), with a total score≥50 indicating internet addiction. Impulsivity was evaluated using the Barratt Impulsiveness Scale-11(BIS-11), and aggression was measured with the Buss-Perry Aggression Questionnaire(BPAQ). Differences in internet addiction, impulsivity, and aggression between the depression group and the control group were analyzed. Pearson correlation analysis was used to explore the correlation between internet addiction and impulsivity, aggression. Hierarchical linear regression models were used to analyze the factors influencing internet addiction, and a parallel mediation model was used to examine the mediating effect of impulsivity and aggressive personality traits in the relationship between depressive disorders and internet addiction.Results:The prevalence of IA was significantly higher in adolescents with depression than the healthy control group [57.75%(41/71) vs 31.33%(26/83); χ 2=10.87, P<0.001]. Adolescents with depressive disorders also exhibited higher impulsivity (65.5±9.2 vs 57.0±9.2, t=-5.72, P<0.001) and aggression (56.3±16.0 vs 42.4±15.1, t=-5.13, P<0.001) compared to the control group. Internet addiction was positively correlated with aggression ( r=0.47, P<0.01) and impulsivity ( r=0.57, P<0.01). Hierarchical regression analysis with the YIAT total score as the dependent variable revealed that impulsivity ( β=0.48, P<0.001) and aggression ( β=0.24, P<0.001) significantly predicted internet addiction. Mediation analysis indicated that depressive disorders indirectly indirectly influenced internet addiction through parallel paths of impulsivity and aggression, with a total indirect effect of 0.543 (95% CI: 0.362-0.761). Conversely, internect addiction influenced depressive disorders through reverse parallel pathway of impulsivity and aggression with a total indirect effect of 0.038 (95% CI: 0.021-0.067). Direct effects were not significant in either direction. Conclusion:Adolescents with depressive disorders exhibit more internet addiction. Impulsivity and aggressive personality traits play bidirectional mediating roles in the relationship between depressive disorders and internet addiction.

Objectives:To analyze the performance and characteristics of adolescent suicide attempters in dif-ferent dimensions of decision making,a computational model was used in this study.Methods:A total of 70 adoles-cent suicide attempters with mood disorders meeting the International Statistical Classification of Diseases and Re-lated Health Problems,Tenth Revision(ICD-10)diagnosis,40 non-suicide attempters with mood disorder,and 49 normal controls were included.By using the MCQ and IGT and through computational model analysis,the adoles-cent suicide attempters'performance and underlying cognitive components in impulsive decision making and value-and learning-based decision making were analyzed.Results:The overall delay discounting rates showed no signifi-cant differences(P＞0.05)among the group of suicide attempters,patient controls,and normal controls in the MCQ.This rate was significantly higher in suicide attempters and non-suicide attempters than in normal controls(P＜0.05);there was no significant difference between the three groups of subjects'decision making performance in the IGT(P＞0.05).Computational model analysis revealed that compared to non-suicide attempters and normal controls,suicide attempters showed reduced sensitivity to the outcome as well as reduced exploratory behavior(Pa-rameter estimate with non-overlapping 80％HDI).Conclusion:Adolescent suicide attempters may not be able to learn from the outcome of the decision and explore more possible options to resolve the crisis,as well as impulsive decision-making impairment may be associated with depressed states rather than suicide attempts.