Caffeine Consumption, Sleep Quality, and Mental Health Outcomes among Jordanian University Students: A Cross-sectional Study

Background: Caffeine is a commonly consumed stimulant among university students, often used to enhance alertness and mood. However, excessive intake has been linked to anxiety and disrupted sleep. While previous research has explored caffeine’s effects on mental health and sleep, findings remain inconsistent, and little is known about these associations among students in the Middle East, particularly in Jordan. Aim: This study investigates the relationship between caffeine consumption, sleep quality, and mental health outcomes – specifically symptoms of depression, anxiety, and stress – among university students in Jordan. Methodology: A cross-sectional online survey was conducted between November 2024 and January 2025 among 853 students from public and private Jordanian universities. Weekly caffeine intake was assessed using items from the Diet and Behaviour Scale questionnaire. Sleep quality was evaluated with the Pittsburgh Sleep Quality Index, and mental health symptoms were measured using the Depression, Anxiety and Stress Scale 21. Data were analyzed using nonparametric tests (Mann–Whitney U -test and Kruskal–Wallis) due to non-normal distribution. Results: Participants (70.9% females; mean age 20.6 ± 2.1 years) reported an average weekly caffeine intake of 771.8 ± 588.8 mg. Poor sleep quality was reported by 70.6% and was significantly associated with higher caffeine intake ( P < 0.001). Caffeine consumption also differed significantly across severity levels of depression ( P = 0.047), anxiety ( P = 0.002), and stress ( P < 0.001), with the highest intake among students reporting extremely severe symptoms. Conclusion: Higher caffeine intake is associated with poorer sleep and greater psychological distress among university students. These findings support targeted interventions to promote moderate caffeine use and improve student well-being.