Persistent poor sleep linked to higher depression risk in college students

In a prospective cohort study of undergraduates at multiple universities in Ningxia, China, students whose sleep quality remained poor over time had a higher incidence of probable depression than peers whose sleep quality gradually improved. The study estimated a relative risk of 5.31 for the persistently poor group compared with the gradually improving group (95% confidence interval, 3.51–8.03; P < 0.001). The results show an association between sleep-quality trajectories and depression risk, rather than establishing that poor sleep caused the difference.

Researchers assessed participants every six months, measuring sleep quality with the Pittsburgh Sleep Quality Index and depressive symptoms with the nine-item Patient Health Questionnaire. A PHQ-9 score of 10 or higher was classified as probable depression. Using a group-based trajectory model, the researchers identified two sleep patterns: a persistently poor trajectory comprising 24.54% of participants and a gradually improving trajectory comprising 75.46%. Modified Poisson regression was then used to compare the incidence of probable depression between the trajectory groups.

The investigators also examined the organization of depressive symptoms with Ising network analysis. Fatigue, represented by PHQ-4, had the highest strength centrality in both sleep-trajectory groups, meaning that it was the most structurally central symptom in the modeled depressive-symptom networks. That structural result did not establish fatigue as the most prevalent symptom or show that it should be the sole focus of an intervention.

A separate computer-simulated network intervention analysis produced different predictive targets for the two groups. Among participants in the persistently poor sleep group, guilt, measured by PHQ-6, showed the largest predicted effect in the simulations. Among those in the gradually improving group, sleep disturbance, measured by PHQ-3, produced the largest projected change in total symptom burden. These are model-based estimates rather than clinical findings: the analysis did not test whether changing either symptom would prevent depression. Taken together, the findings indicate that sleep-quality patterns were heterogeneous and strongly associated with probable depression risk in this undergraduate population, while simulated intervention targets varied by trajectory.

Subject of Research: Sleep-quality trajectories, depression risk, and depressive symptom networks in college students

Article Title: Association between sleep quality trajectories and depression among college students: computer-simulated network analysis

Article References: Niu, Z., Xu, Y., Zhou, L., & Li, J. (2026). Association between sleep quality trajectories and depression among college students: computer-simulated network analysis. BMC Public Health. https://doi.org/10.1186/s12889-026-29911-8

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29911-8

Keywords: sleep quality, college students, depression risk, prospective cohort, symptom networks, network simulation, PHQ-9, mental health, Ningxia, China, Association, between