Mentalizing in Adolescence: Developmental Trends and Associations With Borderline Personality Disorder Features

Impairments in mentalizing, the capacity to understand the self and others in terms of intentional mental states, are proposed to play an important role in the emergence of borderline personality disorder (BPD) in adolescence. Although mentalizing problems in adults with BPD have been amply demonstrated, research in adolescence lags behind in terms of both the normative development of mentalizing in adolescence and the relation between different dimensions of mentalizing and adolescent BPD. Therefore, the current study investigated developmental trends and sex-related differences related to different mentalizing dimensions and the associations between mentalizing dimensions and BPD features in a large group of adolescents (N = 456, M-age = 15.4 years, range = 12-19) oversampled for risk status for psychopathology. The results demonstrated that age was not associated with increases in the capacity for mentalizing, with one exception: externally based mentalizing improved with age. Girls reported greater difficulties in self-focused, internal, and affective mentalizing, but at the same time also higher levels of other-focused, internal, affective, and cognitive mentalizing than boys. Adolescent BPD features were mainly associated with difficulties in understanding, differentiating, and expressing emotions and elevated sensitivity and concern for the feelings of others. Specifically, problems with self-focused, internally based, affective mentalizing best predicted BPD features both categorically and dimensionally. The implications of these findings for our understanding of the relation between mentalizing and BPD in adolescents will be discussed.