Immature defences mediate the association between borderline personality and problematic social media use in generation Z

Introduction: Problematic Social Media Use (PSMU) is increasingly recognised as a relevant public mental health concern. Nevertheless, the main psychological mechanisms underpinning this pattern remain underexplored, especially in Generation Z, for whom social media represents a primary environment for identity construction, interpersonal interaction, information seeking, and self-expression. Grounded in the Interaction of Person-Affect-Cognition-Execution (I-PACE) framework and psychodynamic theory of defence mechanisms, the present study tested whether immature defences mediate the association between Borderline Personality and PSMU. Methods: = 1.66; 252 females) who reported daily social media use completed an online survey, including a brief socio-demographic questionnaire, the Borderline Symptom List-23, the Defence Style Questionnaire-40, and the Bergen Social Media Addiction Scale. Results: Results indicated that immature defences mediated the association between Borderline Personality and PSMU, after controlling for age, sex, education, mature defences, and neurotic defences. Discussion: Overall, these findings suggest that immature defences may represent one psychological process linking Borderline Personality to PSMU, reflecting maladaptive, unconscious strategies of affect regulation. Limitations, theoretical avenues, and clinical implications are discussed.