Aberrant functional connectivity profiles of brain regions associated with salience and reward processing in female patients with borderline personality disorder

Abstract

Recent resting-state functional connectivity studies have shown significant group differences in several networks between patients suffering from borderline personality disorder (BPD) and healthy controls. However, reliable and consistent findings have not been reported yet. Several methodological factors might be responsible for the discrepant findings, including the heterogeneity of patient samples in terms of symptom severity. In the current study, we combined investigations of the whole-brain resting-state functional connectivity patterns of BPD patients with seed-based connectivity measures and then computed the correlation of connectivity measures with borderline symptom severity. Correlation-based connectivity analysis was performed on resting-state functional magnetic resonance imaging (fMRI) data from 26 female BPD patients and 26 healthy controls. Increased intrinsic connectivity was found in clusters involving part of the caudate nucleus and the left insula in the patient group, indicating greater integration of each region. Further seed-based connectivity analyses revealed that with the caudate seed, the patient data exhibited an increased resting-state functional connectivity in the bilateral ventral striatum and the midline prefrontal regions extending to the ACC, a network associated with reward processing. The left insula seed showed significantly increased connectivity with the bilateral fronto-orbital/insula, the inferior parietal lobule and the mid-cingulate cortex, a network involved in attention and salience encoding, in the patient population. Moreover, symptom severity, as assessed with the BSL-95 outside the scanner, was negatively correlated with the coupling of the insula and the striatum in the BPD group. Overall, an increased functional connectivity within two large-scale circuitries underlying reward and salience processing was evident in patients, as compared to healthy participants. When correlated with borderline symptom severity, a reduced connectivity between key regions belonging to the reward system and salience network was observed in the patients. These findings may be helpful for facilitating further understanding of the potential mechanisms underlying the BPD pathophysiology and thereby delineate potential treatment targets.