Polysomnography Indicators Associated With Moderate Depression: A Cross-Sectional Study

Background: This study aimed to use polysomnography (PSG) and clinical rating scales to evaluate sleep quality, sleep characteristics, and their associations in patients with moderate depression. Methods: A total of 52 patients with moderate depression and 21 healthy controls were enrolled. All participants underwent PSG and were assessed using the Pittsburgh Sleep Quality Index (PSQI). Differences in clinical characteristics between the two groups were analyzed. Multivariate binary logistic regression analysis was performed to identify factors associated with moderate depression. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of PSG indicators for moderate depression. Results: Compared with healthy controls, patients with moderate depression exhibited significantly higher total PSQI scores and poorer objective sleep quality based on PSG measurements. Specifically, they had shorter total sleep time (TST), longer wake after sleep onset (WASO), lower sleep efficiency (SE), a higher percentage of wakefulness (W%), fewer rapid eye movement (REM) sleep cycles, and a higher apnea-hypopnea index (AHI) (all p < 0.05). Multivariate binary logistic regression analysis showed that each 1-point increase in the PSQI score was associated with a 6.66-fold increase in the odds of moderate depression (95% CI = 1.143–38.835, p = 0.035). The PSQI score showed excellent discriminative performance (AUC = 0.990, 95% CI: 0.974–1.000), whereas the univariate ROC results for age, ArI, REM cycle, and AHI should be interpreted cautiously as exploratory findings rather than evidence of independent predictive value. Conclusions: Patients with moderate depression exhibit poorer subjective and objective sleep quality than healthy individuals and demonstrate distinct polysomnographic characteristics.