When stress matters most: developmental timing and socio-ecological stressors among Mexican-origin adolescents from low-income immigrant families.

This study investigates the dynamic, time-varying associations between multiple socio-ecological stressors and internalizing symptoms among Mexican-origin youth from low-income immigrant families. Grounded in a socioecological framework and employing time-varying effect modeling (TVEM), we examine how stressors at the interpersonal, family, and neighborhood levels differentially influence anxiety and depressive symptoms across early adolescence (ages 11-13), middle adolescence (ages 14-17), and late adolescence/emerging adulthood (ages 18-20). Participants included 604 Mexican-origin adolescents (54% female) from low-income immigrant families, assessed across three waves spanning nine years. Five distinct stressors were identified: discrimination, foreigner stress, economic stress, language brokering stress, and neighborhood violence/non-safety. Results from TVEM analyses revealed that the impact of discrimination on internalizing symptoms was more pronounced during early and middle adolescence, while foreigner stress became increasingly more pronounced in late adolescence/emerging adulthood. Economic hardship and language brokering stress consistently predicted internalizing symptoms across all developmental periods, whereas neighborhood violence/non-safety exerted the greatest influence during early adolescence. These findings underscore the importance of considering how stressor type and developmental timing intersect to shape mental health outcomes. Moreover, the results suggest that identifying sensitive windows for specific socio-ecological stressors can inform the optimal timing of tailored, developmentally sensitive interventions to mitigate their adverse effects.