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ORIGINAL RESEARCH article

Front. Psychiatry

Sec. Sleep Disorders

Volume 16 - 2025 | doi: 10.3389/fpsyt.2025.1680714

This article is part of the Research TopicInnovative Approaches in Psychosocial and Mental HealthView all 18 articles

Nonlinear Associations of Nighttime Sleep and Protective Napping with Depressive Symptoms: A Cross-sectional Analysis from the China Family Panel Studies

Provisionally accepted
  • 1Nanjing Tech University, Nanjing, China
  • 2School of Athletic Performance, Shanghai University of Sport, Shanghai, China

The final, formatted version of the article will be published soon.

Objective: This study aims to explore the relationship between nap duration, nighttime sleep, and depression among Chinese residents and determine recommended sleep durations to provide scientific evidence for the prevention and control of depression. Methods: Based on the 2020 China Family Panel Studies, demographic data, health, and lifestyle information was obtained from the study subjects. A total of 6,795 valid samples were included. Logistic regression, restricted cubic splines, and stratified linear regression analyses were used to examine the associations between sleep behaviors and depression, including subgroup analyses by health status and age categories. Results: A U-shaped dose–response relationship was observed between nighttime sleep and depressive symptoms (P-nonlinear < 0.001), with the lowest likelihood of depression occurring around 8.5 hours of sleep. A nap duration of 30–90 minutes was associated with a lower likelihood of depression, with no evidence of a nonlinear relationship (P-nonlinear = 0.889). Subgroup analyses revealed that nighttime sleep of 7–9 hours was protective against depression among individuals with self-rated general health or chronic diseases. Age-stratified analyses showed that sleep behaviors had stronger protective effects in young adults (<30 years), whereas depression in middle-aged and older adults (≥30 years) was more influenced by chronic disease status and education level. Conclusion: Nighttime sleep of 7–9 hours and nap duration of 30–90 minutes are associated with reduced depressive symptoms; however, their effects vary across health and age subgroups. These findings highlight the importance of tailoring sleep recommendations to individual characteristics for effective mental health promotion.

Keywords: COVID-19 pandemic, Depression, Nap time, Nighttime sleep, Health Promotion

Received: 06 Aug 2025; Accepted: 06 Oct 2025.

Copyright: © 2025 Song, Liu and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Li Liu, liuli@sus.edu.cn

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