Neural correlates of social inclusion in borderline personality disorder and non-suicidal self-injury

Introduction Recent neuroimaging studies demonstrated a potential disorder-specific neural alteration during social inclusion in borderline personality disorder (BPD) by enhanced activations within the dorsomedial prefrontal cortex (dmPFC) and the posterior cingulate cortex (PCC) when compared to healthy controls (HC) and patients with major depression (MD) (1). To examine the specificity of these neural alterations, we now investigated a sample of patients with BPD and non-suicidal self-injurious behavior (NSSI) and patients with NSSI without BPD compared to HC. In addition, we examined potential neural commonalities during social inclusion considering the strong associations between these two disorders.

Methods A sample of 15 adults with BPD, 16 adults with NSSI and 17 HC were investigated with functional magnetic resonance imaging (fMRI) and the cyberball paradigm. According to our study aim, we focused on differential neural activations under social inclusion versus passive watching. Statistical inference was carried out at p < 0.05 (FWE-corrected on cluster-level). A conjunction analysis on differential neural activations was conducted to examine neural commonalities between these two clinical groups compared to HC under social inclusion (p < 0.05, FWE-corrected for search volume).

Results A significant increase in differential neural activation within the dmPFC was observed in BPD under social inclusion compared to both, NSSI and HC and enhanced activations within these regions were associated to individual borderline symptom severity. In contrast, differential neural activations within the PCC did not differ between BPD and NSSI. A conjunction analysis revealed a common increase in neural activation under social inclusion within the pregenual anterior cingulate cortex (pgACC) and the anterior insula in both, BPD and NSSI compared to HC.

Conclusion Our study provides an evidence regarding a potential disorder-specific neural alteration within the dmPFC in BPD under social inclusion, whereas activations within the PCC may represent a rather unspecific neural alteration in BPD when compared to NSSI. However, both clinical groups revealed common neural increases in regions associated to the affective appraisal of social interaction condition (pgACC, anterior insula) as a potential early neural signature in NSSI without BPD.