AI Insight
This cross-sectional study of 120 college students examined relationships between sleep quality, depressive symptoms, and frontal alpha asymmetry (FAA) measured by EEG. Students with depressive symptoms showed poorer sleep quality and reduced FAA compared to controls, and within the depressed group, poorer sleep quality was associated with lower FAA values, which were both linked to more severe depressive symptoms. The findings suggest FAA may represent a neurophysiological marker connecting sleep disturbances and depression in non-clinical populations, though causation cannot be determined from this study design.
Why it matters
These results identify a potential brain-based biomarker (frontal alpha asymmetry) that could help explain how sleep problems relate to depression in college students. This could inform early detection strategies and guide interventions targeting sleep improvement as a way to support mental health in young adults, though longitudinal research is needed to establish causal relationships.
Understand the Science
BackgroundPoor sleep quality is associated with depressive symptoms, but its accompanying neurophysiological correlates remain unclear in non-clinical college students. This study examined associations among sleep quality, depressive symptoms, and frontal alpha asymmetry (FAA) in students with and without elevated depressive symptoms.MethodsThis cross-sectional study included 120 college students, comprising 60 students with depressive symptoms (DS) and 60 non-depressed controls (NC), classified using the Self-Rating Depression Scale. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and FAA was derived from resting-state EEG. Analyses included BMI-adjusted group comparisons, partial correlations, regression models, and an exploratory indirect-path analysis. False discovery rate correction was applied to multiple comparisons.ResultsAfter BMI adjustment, the DS group had higher PSQI scores [median (P25, P75): 7 (6, 10) vs. 3 (1, 5)] and lower composite FAA values [−0.041 (−0.116, 0.031) vs. 0.056 (0.017, 0.103); both p < 0.001] than the NC group. Similar FAA differences were observed using frontopolar and frontal electrode-pair indices. PSQI scores were positively correlated with depressive symptoms in both groups (DS: r = 0.412, q = 0.006; NC: r = 0.462, q = 0.001). In the DS group, composite FAA was negatively correlated with PSQI (r = −0.322, q = 0.034) and depressive symptoms (r = −0.388, q = 0.010); neither FAA-related association reached statistical significance in the NC group. After BMI adjustment, PSQI and FAA were jointly associated with depressive symptom severity in the DS group (R2 = 0.243). An exploratory indirect-path analysis yielded an indirect association estimate of 0.092 (95% bootstrap CI: 0.002–0.202).ConclusionPoorer sleep quality was associated with greater depressive symptom severity in both groups, whereas FAA-related associations were observed mainly in the DS group. These findings suggest that FAA may be a candidate neurophysiological correlate of the concurrent association between sleep quality and depressive symptoms in non-clinical college students. Causal mediation cannot be inferred from this cross-sectional study.