Substance Use and Non-Suicidal Self-Injury among Adolescents: A Meta-Analysis of Association Patterns and Moderating...

Though previous meta-analyses on the relation between adolescent substance use and non-suicidal self-injury (NSSI) represent important steps toward a better understanding of these typically co-emergent behaviors, their findings remain limited by either broad or select substance type foci, as well as incomplete examination of potentially neglected moderators. This meta-analysis examined associations between substance use and NSSI among a large sample size of adolescents (N = 1,191,255) across 18 studies published between 2007 and 2024. Results revealed moderate positive associations between substance use and NSSI (OR = 1.79, 95% CI [1.39, 2.31]). Stimulants showed the strongest association (OR = 1.93), followed by hallucinogens (OR = 1.76) and depressants (OR = 1.71). Study design (cross-sectional vs. longitudinal) and measurement approaches (categorical vs. continuous vs. combined) moderated some associations, and geographic variations were observed. However, the extremely high heterogeneity across studies (I²>94%) indicates substantial complexity in these relationships that warrants cautious interpretation. These findings reveal how consistent associations across substance types, with stimulants displaying a notably stronger association, suggest shared vulnerabilities during adolescence and possibly common emotion dysregulation mechanisms; clarify the role of region and type of NSSI variable as key moderators with respect to specific substance types; and advance developmental research by clarifying how NSSI and substance use co-develop during adolescence.