Investigating the motivations for non-suicidal self-injury and interpersonal conflict in individuals with and without borderline characteristics

The aim of the study was to explore the differences in the psychophysiological and subjective responses to non-suicidal self-injury (NSSI) and interpersonal conflict (IC) of individuals with and without Borderline Personality Disorder (BPD) characteristics. Specifically, this study aimed to provide further evidence for a potential self-stimulatory function of NSSI and to extend the findings to interpersonal relationships for those with BPD. A personalised staged guided imagery methodology was used to investigate processes at the time of NSSI and IC. Contrary to expectations, the results indicated that interpersonal conflict was generally associated with higher arousal and more distress for both groups. However, and not as expected, only the BPD group reported significantly higher tension during the incident stage of IC than during NSSI. This finding is consistent with prior reports that individuals with borderline personalities have increased emotional reactivity to interpersonal distress. In contrast, subjective responses to NSSI revealed a significant tension reduction following the self-injurious act. This tension reduction model was only significantly evident for the BPD group, therefore and as not expected, providing further support for the affect regulatory function of NSSI in adults with borderline characteristics.