Mediators and moderators of self-injurious behaviours and borderline personality disorder.

Self-harm is a diagnostic criteria of Borderline personality disorder (BPD), and is a significant mental health problem in its own right. Three studies (A/s=46 - 340) are reported that investigated the role of executive functions, attachment orientation, and social cognition as potential mediators and moderators of the relationship between BPD features and self-harm in a non-clinical sample. Findings from Study 1 indicated that personality and attentional control factors interact to determine self-harm likelihood whereby high attentional focusing and shifting abilities are protective when BPD features are low but high focusing may be a possible maintaining factor when BPD features are high. Findings from Study 2 indicated that the individuals who have previously self-harmed exhibited EF deficits compared to controls, particularly deficits primarily related to problem solving, difficulty disengaging attention, and cognitive switching. However, these differences did not influence the relationship between BPD features and self-harm. Instead, self-esteem mediated the relationship between BPD and intent to self-harm after exposure to the vignettes. In Study 3, findings revealed that global self-esteem and attachment anxiety completely mediated the relationship between BPD features and intent to self-harm after exposure to the vignettes. The findings of this study have a number of important implications for definitions, theoretical conceptualisations, and therapeutic interventions.