This systematic review synthesizes empirical research on external risk factors for adolescent smartphone addiction. Scopus and Web of Science were searched for English peer-reviewed empirical articles from 2008 onward; 28 met inclusion criteria (excluding non-adolescents, generic internet addiction, non-empirical work, or non-English). Thematic synthesis organized findings into three external risk domains—family, school, and peers—considering cultural/contextual mechanisms. Family dynamics (parental phubbing, harsh parenting, dysfunction), school stressors, and adverse peer relationships were identified as accumulating, direct and indirect contributors to smartphone addiction. These operate within a techno-ecological framework, where digital technologies amplify vulnerabilities and create new pathways for maladaptive use. Evidence favors an ecological, multi-level perspective. Future research should use longitudinal designs, standardize measures across cultures, and examine understudied regions—especially Africa—to guide culturally sensitive interventions.
Lin et al. (Thu,) studied this question.