Our results showed a significant positive linear relationship between Kessler's Psychological Distress score and the PSQI scores. The highest psychological distress was reported among respondents with poor sleep quality (48.63%). Supporting results from a cross-sectional study conducted by Zhang et al. among young adults (n = 10,123) in the United States illustrated a significant association between sleep patterns and psychological problems (
15). Their study showed that early sleeping correlated with a lower suicide rate while sleeping late, having a short nighttime duration, delaying bedtime on weekends, or having weekend oversleeps linked to mood disorders, anxiety, alcohol and drug use, smoking, and behavioral disorders (
15). Another cross-sectional study conducted by Nuqali et al. among Saudi medical students (n = 219) in Makkah, Saudi Arabia, showed that psychological distress is most prominent among males, and less depressed students had higher GPAs. In addition, psychological distress was mainly reported among students with poor sleep quality (
16). Another local cross-sectional study conducted by Alotaibi et al. among medical students in their preclinical years (n = 282) at a Saudi medical college found that Student's sleep quality was poor and their stress levels were high, with these two factors being substantially related (
17). Another study conducted by Milojevich and Lukowski on the effects of insomnia on mental health showed similar results where individuals with insomnia were more likely to experience somatic complaints, obsessive-compulsive disorder (OCD), depression, anxiety, and psychiatric distress. The study was conducted on undergraduate students (n = 69) and showed that a decrease in sleep quality was associated with increased anxiety and somatization disorder, but not depression (
18). In addition, a longitudinal study in Hong Kong/Macau that sampled Chinese students (aged 18 - 25; n = 930) asserted a bi-directional linkage between sleep and mood. The study demonstrated that quality and quantity of sleep are crucial to optimal brain activity and regulating human emotions (
19). Furthermore, another cross-sectional study on medical students in Saudi Arabia found that sleep deprivation harmed academic performance (78.8%) and mood (78.4%) (
20). Besides, Abdulghani et al. 2021 concluded that getting 6 - 10 hours of sleep per day was associated with normal Epworth Sleepiness Scale (ESS) scores (P = 0.019) and academic grades ≥ 3.75. Also, students with abnormal ESS scores had lower academic achievement, which indicates a significant relationship between abnormal ESS scores, total sleeping hours, and academic performance (
21). On the contrary, a prospective cohort study (n = 102) conducted by Dendle et al. among first-year clinical students (eq. year 3 medical students) at a tertiary hospital-based medical school in Melbourne, Australia, discovered no correlation between students' psychological distress and academic outcomes (
11).