Peripheral inflammation is associated with emotional dysregulation, suicide attempts, and reduced microstructural integrity of white matter in young adults with borderline personality disorder.

BACKGROUND

Borderline personality disorder (BPD) is a psychiatric condition characterized by functional impairment and high rates of suicide attempts. Although its pathophysiology is still unclear, emerging evidence suggests a role of peripheral inflammation. This study investigates the association between peripheral inflammatory markers and clinical, behavioural, and neuroimaging features in individuals with BPD.

METHODS

Seventy-nine BPD patients and 26 controls underwent a multidimensional clinical evaluation, including emotional dysregulation and suicide attempt assessment, and blood sampling for serum cytokine profiling. All the participants received 3 T diffusion-weighted MRI to assess white-matter microstructural integrity. A composite inflammatory index was computed from cytokines' levels and white-matter microstructural integrity was examined in networks relevant to BPD, with a focus on the salience network (SN).

RESULTS

BPD patients showed a significantly elevated inflammatory index (z-score, p = 0.035) primarily driven by increased GM-CSF serum levels (p < 0.026), which in turn were associated with more severe emotional dysregulation (r > 0.26, p < 0.038). BPD individuals with a history of suicide attempts displayed higher inflammatory indices - particularly elevated IL-5 and GM-CSF - compared to both healthy controls and BPD participants without suicide attempts (p < 0.050). Finally, higher inflammatory scores correlated with reduced white-matter microstructural integrity in the anterior SN (r = 0.32, p = 0.043).

CONCLUSIONS

In young adults with BPD, peripheral inflammation is associated with emotional dysregulation, suicide risk, and disruptions of white-matter microstructural integrity of the network involved in external stimuli processing. These findings support a role for immune dysregulation in the neurobiological underpinnings of BPD and underscore the need for further mechanistic research.