Association between nocturia frequency and depression in adults: evidence from NHANES 2021–2023 and a Chinese exploratory cohort

BackgroundNocturia and depression commonly coexist and may share underlying pathways. We examined the cross-sectional association between nocturia frequency and clinically relevant depressive symptoms.MethodsWe analyzed 4,162 adults from the National Health and Nutrition Examination Survey (NHANES) 2021–2023. Nocturia was categorized as 0, 1, 2, or ≥3 voids/night; a Patient Health Questionnaire-9 (PHQ-9) score ≥10 defined clinically relevant depressive symptoms. Survey-weighted logistic regression, an ordinal trend test, and subgroup analyses were conducted. A Chinese cohort (n = 255) was used for exploratory sleep-pathway analyses. A sensitivity analysis used a modified Pittsburgh Sleep Quality Index (PSQI) score excluding the sleep-disturbance component, which includes the nocturnal bathroom-use item.ResultsIn the fully adjusted complex survey model, two voids/night (OR: 1.42; 95% CI: 1.05–1.92; p = 0.026) and ≥3 voids/night (OR: 1.83; 95% CI: 1.40–2.40; p < 0.001) were associated with higher odds of clinically relevant depressive symptoms, with an ordinal trend (p < 0.001). An exploratory age interaction was observed (Wald p for interaction = 0.043). In the Chinese exploratory cohort, the unstandardized indirect effect through total PSQI score was 0.244 (bootstrap 95% CI 0.094–0.426), whereas the total and direct effects were non-significant. A sensitivity analysis excluding the PSQI sleep-disturbance component yielded a smaller but still positive indirect effect (0.181; bootstrap 95% CI 0.053–0.342).ConclusionsFrequent nocturia was cross-sectionally associated with clinically relevant depressive symptoms. The Chinese exploratory outpatient cohort provided exploratory support for a sleep-related statistical pathway, which was attenuated but remained positive after excluding the PSQI sleep-disturbance component. These findings highlight nocturia as a clinically relevant symptom linking urinary, sleep, and mental health, while longitudinal studies are needed to clarify temporal and causal relationships.