University Students’ Sleep and Mental Health Correlates in South Korea

Sleep closely relates to emotional instability. Recent studies report an increase in young adults’ poor sleep and associated mental health problems, including attention deficit hyperactivity disorder (ADHD), anxiety, depression, and so on. However, the information on related modifiable factors of these variables is still lacking. This cross-sectional study examined the association of sleep patterns and sleep quality with ADHD and depression in university students. A total of 290 participants aged 18–27 (Mean = 22.0, SD = 2.1) completed a structured questionnaire consisting of the Pittsburgh Sleep Quality Index (PSQI), the Adult ADHD, and the Center for Epidemiologic Studies Depression scales (CES-D). Of the participants, more than half (52.7%) slept 6 to 8 h per night, and 37% slept less than 6 h. Only 10% reported they went to bed before midnight; 40% went to sleep after 2 am. The mean PSQI score was 5.9 (SD = 2.9) for total participants and significantly correlated with ADHD scores and with depression scores. After adjusting for covariates, PSQI significantly aligned with increased risk for ADHD (β = 0.29, p = 0.036) and depression (β = 0.67; p < 0.001). Late bedtime was a significant factor for depression only. Sleep quality rather than sleep pattern significantly related to ADHD scores, whereas both sleep quality and bedtime aligned with depression scores. Additional studies are needed to develop strategic interventions for university students with ADHD and depression as well as underlying mechanisms.