Background: Investigations into neuroanatomical markers of Borderline Personality Disorder (BPD) have previously yielded mostly mixed results. Findings in adolescent samples are even more limited, and do not match those of adults. The more recent conceptualisations of personality disorders reflected in impairments in personality functioning as a dimensional continuum might provide further insight into potential structural brain aberrations in young people with personality pathology. Therefore, the aim of this study was to investigate brain architecture of personality pathology in adolescents as reflected in this dimensional system. Methods: N=94 female participants aged between 14 and 21 years of age with sub-threshold or full threshold BPD, or healthy controls underwent magnetic resonance imaging and were assessed with the Semi-Structured Interview for Personality Functioning DSM-5 (STiP-5.1), a clinical measure reflecting dimensional impairment in personality functioning. Regression analyses were conducted dimensionally (rather than as group comparisons) to align with the dimensional conceptualisation of the STiP-5.1. Results: N=93 participants were included in the final analyses. No individual brain regions, nor total grey matter volume were significantly associated with the STiP-5.1 (all corrected p≥0.82). The most strongly associated region was the right putamen (uncorrected p value=0.03). When multiple testing was reduced to common ROIs for BPD, there were still no statistically significant associations with the STiP-5.1. Conclusions: While findings failed to yield specific neuroanatomical markers of personality pathology, results may be encouraging for clinicians in that psychotherapy for young people with impairments in personality functioning may not be impeded by aberrant structural alterations in the brain.
