A longitudinal study on the correlation between circadian rhythm and depression in college students

Abstract:

Objective: To explore the stability of circadian rhythm and its correlation with depression and the longitudinal effects in college students. Methods: From September to November, 2018 to 2020, an online questionnaire was issued to assess the circadian rhythm, depression, sleep quality, physical symptoms and life event stress of the freshmen, and they were followed and repeatedly evaluated for two years. Logistic regression model was established to analyze the independent correlation factors of depression in baseline assessment. Mixed effect model was established to analyze the stability of circadian rhythm, longitudinal change of depression and the influencing factors of depression. Results: The detection rate of depression was 24.2%, 52.1% (4 301/8 244) of college students were eveningness, 45.0% (3 708/8 244) were intermedia circadian rhythm, and 2.9% (235/8 244) were morningness. Binary Logistic regression analysis suggested that eveningness (OR=1.526), worse sleep quality (OR=1.540), more serious physical symptoms (OR=1.115), and more stressful life events (OR=1.046) were more likely to have depression mood. The results of mixed effect model suggest that circadian rhythm was still a stable individual characteristic, although the score of morningness-eveningness questionnaire decreases by 1.948 points per year on average. While the standard score for depression increased by an average of 0.104 points per year, analysis of the fixed effects of the model suggested that baseline eveningness (β₀₁=0.028), sleep quality (β₀₂=0.052), physical symptoms (β₀₃=0.017), and life event stress (β₀₄=0.007) positively predicted the increase of standard depression scores. Moreover, students with poorer sleep quality (β₁₂=-0.012) and more stressful life events (β₁₄=-0.002) had a faster increase rate of standard depression score. Conclusion: Although the circadian rhythm is a stable individual characteristic, it will change over time in the college students, and eveningness is one of the important predictors of depression, prompting that circadian rhythm is a crisis intervention for college students’mental health.