is there a correlation between internet use and sleep and cognitive function among medical students?

Background: currently, the internet is widely used by students for academic purposes; however, excessive internet use might have negative consequences on students’ academic performance, sleep quality, and cognitive abilities. objectives: this study aimed to investigate the relationship between internet usage, sleep quality, and cognitive function among medical students. methods: this analytical cross-sectional study was conducted on 525 pre-internship medical students, including 304 first- and second-year students, 113 third-year students, and 108 externs, within 2019 and 2021 at mashhad university of medical sciences, mashhad, iran. the participants were selected using a stratified sampling method. all participants completed the cognitive ability questionnaire (caq), internet addiction questionnaire (iaq), and pittsburgh sleep quality index (psqi). data were analyzed using spss software (version 22). results: according to the iaq, 430 participants (81.9%) were categorized as average internet users, 94 participants (17.9%) had occasional or frequent problems, and 1 participant had significant problems with internet use. mean psqi and caq scores were significantly higher among participants with occasional or frequent problems/significant problems than the average internet users (p < 0.001 each). the total iaq score showed a positive correlation with total caq (r = 0.439, p < 0.001) and total psqi (r = 0.264, p < 0.001) scores. among the psqi subscales, sleep latency (p = 0.032), daytime dysfunction due to sleepiness (p < 0.001), sleep efficiency (p = 0.001), and overall sleep quality (p < 0.001) were worse in participants with occasional or frequent problems/significant problems than in average internet users. conclusions: excessive internet use negatively affects the sleep quality and cognitive performance of medical students.