Depression has been a pressing mental health concern among contemporary adolescents. Accumulating evidence suggests that individuals' circadian preference-chronotype-may be associated with adolescent depression, yet the potential mediating and moderating roles within this association have received limited attention in existing research. The present study aimed to examine the relationship between chronotype and depression among adolescents, as well as the mediating role of bedtime procrastination and the moderating role of parental psychological control. A cross-sectional study was conducted among 4324 adolescents (63.9% female; mean age = 16.24 ± 0.92 years) using a questionnaire survey method. All participants completed self-report measurements, including the Composite Morningness Questionnaire (CMQ), Bedtime Procrastination Scale (BPS), Patient Health Questionnaire-9 (PHQ-9), and Parental Psychological Control Scale (PPCS). The results showed that chronotype was significantly and negatively associated with depression among adolescents (β = -0.461, p < 0.001). Bedtime procrastination partially mediated the association between chronotype and adolescent depression (β = -0.257, 95%CI [-0.283, -0.232]), with a mediating effect size of 55.75%. Moreover, parental psychological control moderated the direct association between chronotype and depression (β = -0.043, 95%CI [-0.070, -0.016]), as well as the association between bedtime procrastination and depression (β = 0.120, 95%CI [0.092, 0.148]). Specifically, high levels of parental control were linked to a more pronounced relationship between chronotype and depression, as well as a stronger association between bedtime procrastination and depression. These findings advance our understanding of how chronotype is related to adolescent depression, and suggest that multilevel interventions targeting sleep hygiene practices and family dynamics may be promising for reducing depressive risk among vulnerable adolescents. However, given the cross-sectional design, future longitudinal or experimental studies are needed to establish temporal precedence and further test these associations.
