# Associations of physical activity, sedentary time, sleep quality, and resting EEG with mild depressive symptoms in college students: a cross-sectional study

## TL;DR

College students with mild depressive symptoms show less physical activity, more sedentary time, worse sleep quality, and altered brain activity in resting EEG.

## Contribution

This study identifies behavioral and neural patterns associated with mild depressive symptoms in college students using physical activity, sleep quality, and resting EEG data.

## Key findings

- MDS group showed reduced physical activity and increased sedentary time and sleep disturbances compared to the ND group.
- Resting EEG in MDS group showed increased Alpha2 and Beta1 band power in specific brain regions.
- EEG indicators combined achieved an AUC of 0.659 for identifying mild depressive symptoms.

## Abstract

This cross-sectional study aims to describe the characteristics of physical activity, sedentary time, sleep quality, and resting EEG among college students with mild depressive symptoms, and further explore pairwise correlations between behavioral patterns, resting EEG, and mild depressive symptoms.

This study included 75 college students with mild depressive symptoms (MDS) and 75 college students without depressive symptoms (ND) as research subjects. Physical activity (vigorous physical activity (VPA), moderate physical activity (MPA), and low physical activity (LPA)) and sedentary time（ST） were measured using the International Physical Activity Questionnaire Short Form (IPAQ-SF). Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Resting EEG power values were collected from subjects in a quiet, eyes-closed state using an electroencephalography (EEG) device.

(1) Characteristic analysis revealed that compared with the ND group, the MDS group exhibited reduced MPA and VPA scores, elevated ST scores, and increased total PSQI scores along with elevated scores across its subdimensions. Their behavioral patterns (Moderate-to-Vigorous Physical Activity (MVPA), Sedentary Behavior (SB), Poor Sleep Quality (PSQ) may have changed, including a decrease in the proportion of MVPA, an increase in the proportion of SB, and an increase in the proportion of PSQ. Analysis of resting EEG revealed increased Alpha2 (α2) band power in the temporal regions (T3 and T5) and increased Beta1 (β1) band power in the frontal region (Fp1) in the MDS group (all p
FDR < 0.01). (2) Exploratory analyses revealed that SB and PSQ behaviors may be positively correlated with mild depressive symptoms, while MVPA may be negatively correlated with mild depressive symptoms. The combination of certain EEG indicators (α2 at T3 and T5, β1 at Fp1) achieved an AUC of 0.659 (95% CI: 0.572 to 0.745, p = 0.001) for identifying mild depressive symptoms. Additionally, in the MDS group, sleep efficiency scores showed a negative correlation with Alpha1 (α1) band power at the frontal region (F4) electrode position, sleep disturbance scores showed a negative correlation with theta (θ) band power at the parietal region (P3), hypnotic medication scores showed a positive correlation with beta1 (β1) band power at the frontal region (F3), and total PSQI scores showed a negative correlation with θ band power at the temporal region (T3).

College students with mild depressive symptoms may exhibit altered behavioral patterns and abnormal neural activity in the frontal and temporal regions. Their changed behavioral patterns may correlate with mild depressive symptoms, and recognition models based on certain resting EEG indicators demonstrate preliminary application potential. The association between specific sleep issues and localized EEG activity in this population may provide evidence for further elucidating the mechanistic pathways linking their behavior and brain activity. Future longitudinal studies are recommended to explore causal relationships among these variables.