Mediating mechanisms between academic stress and internalizing problems in adolescents: a systematic review and meta-analysis

Background Perceived academic stress is closely associated with internalizing problems in adolescents, but evidence regarding the mechanisms mediating this association remains fragmented. This study aimed to systematically identify and quantitatively synthesize different mediating mechanisms while separately examining self-harm- and suicide-related outcomes. Methods APA PsycINFO, CNKI, ERIC, Embase, PubMed, Scopus, and Web of Science were systematically searched from database inception to July 2, 2026. Quantitative studies of adolescents that examined the “perceived academic stress–mediator–internalizing problems” pathway were included. Standardized indirect effects (ab) were pooled using random-effects models, and the stability of the findings and certainty of evidence were evaluated using leave-one-out sensitivity analyses and the GRADE framework. Results A total of 29 study reports comprising 31 independent samples and 114,498 adolescents were included. For general internalizing problems, significant indirect effects were observed for emotion–cognition mechanisms (ab = 0.126, 95% CI 0.061–0.191), self- and school-adjustment mechanisms (ab = 0.098, 95% CI 0.030–0.165), and behavioral and lifestyle mechanisms (ab = 0.030, 95% CI 0.006–0.054), whereas the indirect effect of social connectedness mechanisms was not statistically significant (ab = 0.059, 95% CI − 0.015–0.133). The first two mechanisms remained stable in sensitivity analyses, whereas the behavioral and lifestyle mechanism was sensitive to individual studies. For self-harm- and suicide-related outcomes, seven study-level indirect-effect estimates from five reports were examined descriptively according to their outcome definitions, without pooling across clinically distinct endpoints. Substantial heterogeneity was observed in all primary analyses. The certainty of evidence was moderate for the first three mechanisms and low for the social connectedness mechanism. Conclusion Perceived academic stress may be associated with adolescent internalizing problems through multiple pathways, with relatively stable support found for emotion–cognition and self- and school-adjustment mechanisms. The robustness of the behavioral and lifestyle pathway was limited, and evidence regarding social connectedness remained inconsistent. Because the existing studies predominantly used observational designs, these findings should not be interpreted causally. Further validation through multi-wave longitudinal and experimental studies is needed. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261465222 . The systematic review was registered in PROSPERO under registration number CRD420261465222.