Internalizing and Externalizing Problems in Adolescence: The Role of Borderline and Narcissistic Personality Traits

Introduction. Adolescence is a sensitive period for developing internalizing and externalizing problems, and extensive research has shown that borderline personality traits may significantly impact both. Conversely, the relationship between narcissistic personality traits and internalizing and externalizing problems in adolescence has been understudied. The present study examines the current contribution of borderline and narcissistic personality traits to the presence and maintenance of internalizing and externalizing problems in adolescence. Methods. We conducted a two-wave study on a sample of adolescents (N baseline = 705; 65% F; Mage = 15.84, SD = 1.31; N follow-up = 186). They were asked to complete self-reported measures of borderline and narcissistic traits at the baseline and internalizing and externalizing problems at the baseline and the follow-up. Regression analyses were performed to examine the associations of borderline and narcissistic personality traits with the presence and maintenance of internalizing and externalizing problems. To account for gender-related patterns of associations and predictions, regression models were conducted separately on males and females. Results. Borderline personality traits were significantly related to both the presence and maintenance of internalizing and externalizing problems in both males and females. Moreover, grandiose narcissistic traits showed to be predictive of externalizing problems after 12 months in males only. Discussion. The study provides evidence of a significant but differential contribution of borderline and narcissistic personality traits to the presence of co-occurring internalizing and externalizing problems in adolescents and their maintenance over time.