Abstract
BACKGROUND: Medical students experience high stress, often leading to increased caffeine consumption as a coping mechanism. The relationship between specific stressors and caffeine expectancy—beliefs about caffeine’s effects—is poorly understood in the Saudi context. AIM: This study aimed to examine the association between perceived stress levels and caffeine expectancy among medical students (n = 500), exploring how stress may affect different domains of caffeine-related beliefs and behaviors. METHODS: A cross-sectional study was conducted among 500 medical students in Jeddah, Saudi Arabia, using an online questionnaire. It included demographic data, the Brief-Caffeine Expectancy Questionnaire (B-CaffEQ), and the Medical Student Stressor Questionnaire (MSSQ). Data were analyzed using correlation and multivariate regression. Results: Participants (mean age 22 ± 2 years; 64.2% female) reported high stress, particularly in academic domains. Total stress was strongly correlated with total caffeine expectancy (r = 0.597, p < 0.0001), and academic stress was strongly correlated with energy/work enhancement expectancy (r = 0.59, p < 0.0001). Regression analysis identified stress as the strongest positive predictor of caffeine expectancy (β = 0.583, p < 0.0001), while attending a private college was a negative predictor (β = −0.100, p = 0.007 indicating that students in private colleges reported lower caffeine expectancy scores compared with those in public institutions. CONCLUSION: Perceived stress emerged as the strongest statistical independent variable affecting caffeine expectancy in the regression model. Students under high academic pressure develop strong expectations that caffeine will enhance performance. Addressing the root causes of academic stress and promoting healthier coping strategies is crucial for student wellbeing. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s44192-026-00412-9.