Abstract: The causal relationship between peer exclusion and depressive symptoms in children and adolescents remains controversial. Three competing theoretical models offer divergent predictions. The stress process model views peer exclusion as a chronic interpersonal stressor that triggers depressive symptoms. The symptom-driven model argues that depressive symptoms actively elicit peer exclusion. The transactional model proposes a bidirectional vicious cycle. Despite the theoretical importance of clarifying this relationship, existing empirical findings remain inconsistent. Moreover, no prior meta-analysis has systematically synthesized longitudinal evidence using meta-analytic structural equation modeling (MASEM).
To address these gaps, a systematic literature search was conducted across eight Chinese and English databases: Web of Science Core Collection, Medline, Elsevier, EBSCO-ERIC, PsycINFO, PsycArticles, ProQuest Dissertations & Theses Global, and China National Knowledge Infrastructure. The search had no start date restriction and a cutoff date of October 18, 2025. A total of 23 longitudinal studies (26 independent samples, N = 20,676) met the inclusion criteria. Two independent reviewers performed study screening, data coding, and quality assessment using the Joanna Briggs Institute Critical Appraisal Checklist, with inter-rater agreement exceeding 95%. One-stage MASEM was conducted via the webMASEM platform using full information maximum likelihood estimation with random-effects models. Publication bias analyses indicated minimal bias. Egger‘s regression was not significant (p = 0.96). The p-curve analysis exhibited significant right-skewness. Trim-and-fill correction yielded negligible changes in the pooled effect size.
The main effect analysis revealed significant bidirectional associations. Peer exclusion at T1 significantly predicted subsequent depressive symptoms at Tn (β = 0.06, p = 0.04). Depressive symptoms at T1 significantly predicted subsequent peer exclusion at Tn (β = 0.09, p = 0.02). These findings support the transactional model. Moderator analyses revealed several notable findings. Cultural background significantly moderated the depressive symptoms → peer exclusion path (β = -0.03, p = 0.09, marginal) and the autoregressive path of depressive symptoms (β = -0.06, p = 0.02). Higher individualism scores were associated with weaker predictive effects and lower stability of depressive symptoms. Peer exclusion reporting method significantly moderated the depressive symptoms → peer exclusion path (β = -0.21, p = 0.003). Self-report measures yielded stronger effects than other-report measures. Publication year showed a marginally significant positive moderating effect (β = 0.06, p = 0.07), suggesting that this effect may have strengthened over time. Time interval negatively moderated both autoregressive paths. In contrast, mean age and sex ratio showed no significant moderation.
This study preliminarily reconciles the theoretical debates among the stress process model, the symptom-driven model, and the transactional model. It confirms that peer exclusion and depressive symptoms in children and adolescents have a bidirectional predictive relationship. The two constructs form a vicious cycle, providing meta-analytic evidence for the transactional model.
The findings suggest that mental health interventions should shift from single-path approaches to dual-track strategies. Practitioners should reduce the occurrence and psychological harm of peer exclusion while simultaneously improving the social interaction patterns of depressed individuals, thereby interrupting the mutual reinforcement between the two. Meanwhile, cultural background significantly moderates the effect of depressive symptoms on subsequent peer exclusion and the stability of depressive symptoms. In collectivistic cultures, interventions should emphasize group support, family involvement, and destigmatization education. In individualistic cultures, greater emphasis can be placed on promoting active help-seeking and emotional self-regulation. Moreover, reporting method significantly affects the effect size of depressive symptoms predicting peer exclusion, suggesting that future research should combine self-report and other-report measures. Finally, the marginal positive moderating effect of publication year on the depressive symptoms → peer exclusion path suggests that the digital social era may have amplified the interpersonal consequences of depressive symptoms. Future efforts should guide adolescents to use the internet wisely, balance online and offline social activities, and prevent depressed individuals from falling further into social isolation due to excessive reliance on digital interaction.

Key words: peer exclusion, depressive symptoms, longitudinal study, meta-analytic structural equation modeling