Better Mental Health and Sleep under Behavioral Restrictions Due to COVID-19 in Japanese University Students: A Cross-Sectional Survey.

Coronavirus disease (COVID-19) is a global pandemic, which is not only a severe public health issue but also significantly impacts the physical activity, sleep habits, and mental health of university students. Thus, we examined the association between behavioral restrictions due to COVID-19 and sleep patterns and mental health in first-year Japanese university students. Four hundred and twenty-two students (253 males and 169 females; age, 18.7 ± 1.0 years) participated in our questionnaire study. Under the behavioral restrictions due to COVID-19, 193 students (127 males and 66 females) responded to the questionnaire online from home. The participants did not visit the university during the survey period. The data acquired the year before the COVID-19 pandemic (2018 and 2019) were used as control data (126 males and 103 females). The questionnaire consisted of four sections: (1) demographic and lifestyle variables, (2) the Pittsburgh Sleep Quality Index, (3) the Japanese version of the Epworth Sleepiness Scale, and (4) the Patient Health Questionnaire-9. Our data revealed that self-restraint due to COVID-19 was associated with better sleep and mental health. In addition, mental health was independent of sleep, while sleep was related to mental health. These differences were more pronounced in male than in female students. This finding could be due to physical activity at night, part-time work, and long commuting times during the pre-pandemic period.