Assessment of neurotransmitter-related structural brain changes in borderline personality disorder: an MRI study

Borderline personality disorder (BPD) is characterized by grey matter (GM) alterations in areas related to emotion regulation, impulsivity and metacognitive abilities. Dysfunction of specific neurotransmitters, including serotoninergic and dopaminergic systems, is thought to be involved, but evidence is currently limited. In this exploratory study, we tested for associations between GM alterations in BPD, the spatial distribution of neurotransmitter systems, and clinical features in a sample of 58 patients with BPD and 28 healthy controls (HC). GM volume alterations were assessed on 3T MRI using voxel-based morphometry (i) in BPD patients compared to HC and (ii) between BPD subgroups defined based on clinical features followed by spatial correlations between regional GM differences and atlas-based neurotransmitter maps. We observed smaller GM volumes in BPD patients compared to HC in the limbic, temporo-parietal, frontal medial, olfactory, and cerebellar regions (p_FDR<0.05), but no association between these GM abnormalities and neurotransmitter maps of serotoninergic, dopaminergic, noradrenergic, glutamatergic, GABAergic, opioid and endocannabinoid systems (p_FDR>0.05). Our results do not support the notion of a direct relationship between BPD-related GM alterations and specific major neurotransmitter systems, highlighting the need for additional studies to determine the pathophysiologic mechanisms underlying structural changes.