Borderline Personality Disorder in Young People : Complexities in Understanding of and Relating to Others

The expanding research on Borderline personality disorder (BPD) increasingly confirms continuity from adolescence to adulthood, in phenomenology, structure, stability, validity and morbidity. This has led to a more developmental perspective on BPD. The current thesis aims to contribute to the understanding of the development of BPD by investigating associations between cluster B personality pathology, and BPD particularly, with mentalizing reflected in social information processing (SIP) and relationships with parents and peers. Chapter 2 integrates two research traditions targeting the understanding of BPD in adolescents; 1) personality according to the Five Factor Model and 2) mentalizing capacities reflected in social information processing (SIP). In a clinical adolescent sample, the hypothesized effects of personality dimensions on personality pathology, was found only for the Neuroticism, most specifically on BPD. This link was mediated by reported memories about past frustrating/conflict situations with peers. Moderating effects suggested that high Agreeableness and sometimes low Neuroticism can buffer the link between SIP and personality pathology. The findings in Chapter 3 showed that the more severe the cluster B personality pathology, the higher the intensity of reported emotions; the more likely adolescents were to choose inadequate coping strategies and aggressive reactions in social situations; and the more positively they evaluated aggressive reactions. Severity of ASPD and BPD had unique associations with distinctive SIP-variables: ASPD being more related to inadequate coping strategies, less reflection on other’s motives, and aggressive responses; while BPD being more related to avoidant or prosocial responses and in particular to memories of frustrating events. In chapter 4 it was demonstrated that adolescents with more BPD symptoms experienced less parental support and more negative interactions with parents. Multiple regression analyses demonstrated that negative interactions with parents - but not with best friends - are related to symptoms of BPD. Relationships with best friends did not buffer or reinforce the effect of negative interactions with parents. Chapter 5 investigated whether BPD could be predicted by adverse childhood experiences; and the quality of current relations in adolescents with nonsuicidal self-harm (NSSI) disorder referred to mental health care. Higher levels of BPD were related to increased adverse childhood experiences, but not to current social relations. Current social relationships with parent and peers did not show a buffering effect in the relation between adverse childhood experiences and BPD, with the exception of adolescents with full BPD, where a combined effect of adversity and parent relations was found. The closing chapter integrates the results of the previous chapters, indicating that several SIP factors seem to contribute to the understanding of BPD. Relationships with parents, and negative interactions in particular, can play a profound role in adolescents with BPD, as they cannot be compensated for nor buffered by relationships with best friends. Although adverse childhood experiences were highly correlated with current relations with parents, they could not be compensated for by current relations with parents and peers, indicating that parental relations set the stage for psychosocial relations more in general within BPD