Peripheral CD4+ T helper lymphocytes alterations in major depressive disorder: A systematic review and meta-analysis.

Previous research has shown that patients with major depressive disorder (MDD) develop immune dysfunction. However, the exact alterations of cluster of differentiation (CD)4+ T helper (Th) lymphocytes in MDD remains unclear. This meta-analysis aimed to examine the specific changes in CD4+ Th cells. A comprehensive search of PubMed, EMBASE, Web of Science, and PsycINFO databases was conducted to identify studies investigating CD4+ Th, Th1, Th2, Th17, and T regulatory (Treg) cell counts in the peripheral blood of MDD patients and healthy controls (HCs), covering the period up to June 22, 2024. Our findings revealed that patients with MDD might exhibit higher CD4+ Th cells (SMD=0.26, 95 %CI, 0.02 to 0.50), CD4+/CD8+ cell ratios (SMD=0.51, 95 %CI, 0.14 to 0.89), Th1/Th2 cell ratios (SMD=0.15, 95 %CI, 0.01 to 0.30) and lower Th1 (SMD=-0.17, 95 %CI, -0.30 to -0.03), Th2 (SMD=-0.25, 95 %CI, -0.40 to -0.11), and Treg cells (SMD=-0.69, 95 %CI, -1.27 to -0.11). However, no significant difference was observed in terms of Th17 cells and Th17/Treg cell ratios between MDD patients and the HCs. Heterogeneity was large (I2:18.1-95.2 %), and possible sources of heterogeneity were explored (e.g., age, depression scale, country, and antidepressant use). Our findings indicate that peripheral CD4+ T cells in depressed patients exhibit features of adaptive immune dysfunction, as evidenced by increased CD4+ Th cells and CD4+/CD8+ and decreased Treg cells. These findings offer insights into the underlying mechanism of MDD.

Inconsistency in psychological resilience and social support with mental health in early adolescents: A multilevel response surface analysis approach.

BACKGROUND: Given the high prevalence of adolescent mental health problems, promoting understanding and implementation of protective factors is crucial for prevention and intervention efforts addressing adolescent mental health problems. This study aims to investigate whether consistency and inconsistency in protective factors are associated with adolescent mental health problems and to inform adolescent mental health interventions that target the unique needs of adolescents and promote adolescent mental health. METHODS: We used multistage cluster sampling to conduct psychological resilience, social support, and mental health questionnaires from April to June 2023 among 10,653 Chinese adolescents (52.3 % were boys). Data were analyzed using polynomial regressions with response surface analysis. RESULTS: The higher levels of psychological resilience and social support in adolescents were associated with fewer mental health problems (anxiety: a1 = -1.83, P < 0.001; depression: a1 = -2.44, P < 0.001; and perceived stress: a1 = -1.20, P < 0.001). When the level of psychological resilience was greater than social support, the greater the discrepancy the higher the perceived stress among adolescents (a3 = 1.19, P < 0.001). Moreover, the consistency of psychological resilience and social support had a greater impact on girls' mental health (anxiety: a1 = -1.97, P < 0.001; depression: a1 = -2.71, P < 0.001; perceived stress: a1 = -1.23, P < 0.001). LIMITATIONS: The cross-sectional study design limited the inference of causal relationships between variables. CONCLUSIONS: These results emphasize that adolescents need a balanced development of protective factors and targeted intervention programs for different mental health problems.

Longitudinal and Reciprocal Effects in the Association Between School Bullying and Homicidal Ideation During Early Adolescence.

Several cross-sectional studies indicated a positive association between school bullying and homicidal ideation during early adolescence. However, few longitudinal studies investigated this association. This study examined whether a bi-directional relationship exists within the longitudinal association between bullying victimization or bullying perpetration and homicidal ideation among early adolescents using a Random Intercept Cross-Lagged Panel Model. A total of 1611 early adolescents (39.5% girls; Mage = 12.50 years, SD = 0.50) were recruited from the Chinese Early Adolescents Cohort study. Data on bullying victimization, bullying perpetration, and homicidal ideation collected during three time points (September 2019, September 2020, and September 2021) were used. Bullying victimization showed a significant positive association with homicidal ideation at the between-person level. Bullying victimization and bullying perpetration had a bi-directional relationship with homicidal ideation at the within-person level. Additionally, this study considered the impact of biological sex-based differences and bullying types on adolescents' homicidal ideation. Based on these findings, school bullying might exhibit unique reciprocal associations with homicidal ideation.