The study investigated the impact of screen time on intelligence, attention, and academic performance in second-year medical students at UNAM during the 2023 academic year. The Shipley-2 tests for measuring fluid (Gf) and crystallized intelligence (Gc), the Youth Screen Time Survey, and official physiology scores were used. Network analysis identified six clusters of variables, with number of courses failed, total screen time, and age being the most influential. Text messages and short videos like TikTok served as bridges between digital behavior and academic performance. Higher screen time was associated with lower academic performance (r ≈ −0.24) and reduced fluid intelligence, with crystallized intelligence relatively unaffected. Findings show an association of excessive digital exposure with poorer cognitive performance and academic performance.