The effects of allostatic load, bullying, and social mobility belief on depression among socioeconomically disadvantaged Chinese adolescents.

Allostatic load (AL), the cumulative physiological cost of early adversity, is associated with increased depression risk, especially among disadvantaged adolescents. Bullying, which peaks during adolescence, also predicts depressive symptoms. However, how early (e.g., AL) and recent (e.g., bullying) stressors interact to influence adolescent depression remains unclear. While social mobility belief-adolescents' expectations of upward socioeconomic movement-is often viewed as protective, its effects may vary under stress. Based on the biopsychosocial model, this study examines the interplay among AL, bullying, and social mobility belief in shaping adolescent depression. Participants were 600 adolescents (Mage = 11.44, SD = 1.76; 49.17% boys) from impoverished rural areas in China. Data were collected at two time points at 1-year intervals. Adolescents completed questionnaires assessing bullying experiences, social mobility belief, and depressive symptoms. AL was measured using eight biomarkers: heart rate, systolic and diastolic blood pressure, body mass index (BMI), cortisol, epinephrine, norepinephrine, and dehydroepiandrosterone. Results indicated that AL and bullying exert cumulative effects on depression: bullying predicted higher depressive symptoms among adolescents with high AL, but not among those with low AL. This relationship was further moderated by social mobility belief. A higher social mobility belief may exacerbate depression in adolescents with high AL who face significant bullying. These findings highlight that the role of social mobility belief is context-dependent, rather than a universally protective factor and suggest that interventions should address both physiological stress and perceived opportunity.