This mixed-methods study examines the impact of childhood trauma and family dynamics on mental health and the development of social media use disorder (SMUD) among university students. Through a combination of quantitative and qualitative methods, this research offers a comprehensive investigation into how early life experiences influence social media addiction and the mediating role of mental health. The independent variable is childhood experiences, the dependent variable is social media use disorder, and mental health serves as the mediating variable. The study, conducted in 2024 with a sample of 330 university students, employs correlation analysis and mediation testing, with bootstrapping used to evaluate the significance of indirect effects. The results demonstrate that mental health issues, such as depression, anxiety, and stress, mediate the relationship between childhood experiences and social media use disorder. Structural Equation Modeling (SEM) further reveals that adverse childhood experiences contribute to mental health challenges in adulthood, which in turn exacerbate social media addiction. Qualitative findings offer rich insights into how social media affects daily routines, family interactions, and psychological well-being, revealing its central role in the participants' lives. Moreover, this study highlights how childhood experiences shape social media use patterns. These findings significantly advance the understanding of the complex interplay between early life trauma, mental health, and social media use, addressing critical gaps in the literature on digital addiction.