ABSTRACT
While the association between parent-child relationships and adolescent depressive symptoms is established, their developmental trajectories, particularly their co-developmental dynamics, and underlying mechanisms in Chinese early adolescents remain underexplored. Grounded in depression personality susceptibility theory, this study examined the longitudinal changes in these variables and tested perceived stress as a key mediator. A sample of 604 Chinese early adolescents (N = 604; Mage = 13.88) was followed across three waves over one year. Parallel process latent growth curve modelling and longitudinal mediation models with random intercepts were applied to analyse the data. Across three waves over 1 year, Parent-child relationship quality demonstrated a linear decline during early adolescence, whereas perceived stress and depressive symptoms demonstrated a linear increase. No significant association was observed between parent-child relationship quality and depressive symptoms at baseline or rates of change. Predictive effect at the between-person level was not significant, and T1 parent-child relationships did not predict T3 depressive symptoms at the within-person level. Perceived stress had a significant mediating effect at the initial level, rate of change, and between-person level. At the within-person level, T1 parent-child relationship quality predicted T3 depressive symptoms through T2 perceived stress, supporting longitudinal mediation. These findings highlight the mediating role of perceived stress, clarify the temporal relation between parent-child relationships and depression, offer theoretical support for adolescent depression alleviation and practical insights for school-based prevention.