The Association of Borderline Personality Features and Self-Injury Among Adolescents with Non-Suicidal Self-Injury: The Mediating Role of Alexithymia

Introduction: Non-suicidal self-injury (NSSI) is becoming an increasingly prevalent phenomenon among adolescents, endangering their health. The aims of this study were to 1) explore the associations between borderline personality features, alexithymia and NSSI and 2) examine if alexithymia mediates the relationships between borderline personality features and both the severity of NSSI and the various functions that maintain NSSI in adolescents.Methods: This cross-sectional study recruited 1779 outpatient and inpatient aged 12-18 years from psychiatric hospitals. All adolescents completed a structured four-part questionnaire including demographic items, the Chinese version of the Functional Assessment of Self-Mutilation, the Borderline Personality Features Scale for Children and the Toronto Alexithymia Scale.Results: The structural equation modelling results indicated that alexithymia partially mediated the associations between borderline personality features and both the severity of NSSI and the emotion regulation function of NSSI (B = 0.058 and 0.099, both p < 0.001), after controlling for age and sex.Discussion: These findings suggest that alexithymia may play a role in the mechanism and treatment of NSSI among adolescents with borderline personality features. Further longitudinal studies are essential to validate these findings.