Prevalence and associations of biological rhythm disorders with depression and anxiety symptoms in Chinese adolescents: A multicenter study across seven provinces

Biological rhythm disruption is increasingly implicated in adolescent emotional ill-health. We conducted a multicenter cross-sectional survey of 9,498 senior high school students (15–18 years) from seven Chinese provinces. Depressive and anxiety symptoms were assessed with the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7, and biological rhythm disruption—spanning sleep, dietary, daily-activity, and electronic-use rhythms—was measured using the Self-rating Questionnaire of Biological Rhythm Disorders for Adolescents. In this large sample, the prevalences of depressive symptoms, anxiety symptoms, and their co-occurrence were 48.8%, 47.6%, and 39.6%, respectively. Compared with low disruption, high total rhythm disruption was strongly associated with depression (OR 15.30, 95% CI 13.32–17.59), anxiety (OR 11.91, 10.39–13.64), and comorbidity (OR 14.83, 12.78–17.20). Clear dose–response patterns were observed across total and subdimension scores and symptom severity, with particularly pronounced associations for dietary and daily-activity rhythms. Subgroup analyses indicated stronger associations among girls, urban students, and adolescents aged ≥ 17 years. By jointly evaluating overall rhythm-disruption burden, domain-specific rhythm dimensions, symptom co-occurrence, and subgroup differences, this study extends existing evidence on biological rhythm disorder and adolescent emotional symptoms. These findings highlight biological rhythm disruption as a salient correlate of common emotional symptoms among senior high school students sampled across seven Chinese provinces and support school-based strategies that stabilize daily routines—regularizing meal timing and activity schedules, limiting late-night screen exposure, and strengthening sleep hygiene. Given the cross-sectional design, causal inference is not possible; longitudinal and interventional research is warranted to clarify mechanisms and test rhythm-focused prevention.