The interplay between attention deficit/hyperactivity disorder and internet addiction: executive dysfunction and insomnia as mediators and the role of physical activity

Background: Attention Deficit/Hyperactivity Disorder (ADHD) and internet addiction (IA) are common among college students and often co-exist. This study investigated the relationship between ADHD symptoms, executive dysfunction, insomnia, and IA in Chinese college students. Methods: A cross-sectional study was conducted in June 2024 at six universities in Hunan Province, China. Demographic data and symptoms of ADHD, IA, executive dysfunction, insomnia, and physical activity were collected via interviews and self-reported questionnaires. Physical activity level was further quantified and categorized using metabolic equivalents (METs) method. Mediation models were performed to explore the path from ADHD to IA and the role of physical activity in IA symptoms. Results: Among 1925 students, 12.52% had ADHD symptoms, and 14.03% had IA symptoms. ADHD symptoms were related to IA symptoms (total effects: 0.38, p < 0.001; direct effect: 0.111, p = 0.003), mediated by insomnia (0.161, p < 0.001) and executive dysfunction (0.108, p < 0.001). Compared with no physical activity, moderate-level and high-level physical activities were negatively correlated with IA symptoms, with total relative standardized effects of -0.18 (p = 0.001) and -0.42 (p