(PS10-C65) Cortical Thickness Links to Borderline Personality Disorder Severity in a Diverse Community Sample

Introduction: Borderline Personality Disorder (BPD) is a severe form of psychopathology characterized by emotion dysregulation, interpersonal dysfunction, and impulsivity. While there have been many studies devoted to examining the neuroanatomical abnormalities associated with this disorder, most of these studies have compared BPD patients with healthy controls. Given the growing interest in dimensional models of psychopathology, research is now needed to explore the neural correlates of BPD across a spectrum of symptom severity.

Aims: The primary aims of this study are 1) to investigate the neuroanatomical bases of BPD severity and 2) to examine where these neuroanatomical regions relate to other clinical outcomes, such as lifetime trauma exposure and risky behavior.

Methods: An unselected community sample of 187 adults [M(SD)age = 30.17(8.72) years old; 48.7% female] completed two phases of a research study. The sample was socioeconomically (median household income = $42,000), ethnically (13% Hispanic or Latino) and racially diverse (32% Black or African American, 9% Asian, 60% White). More than 32% of the sample reported being arrested at least once in their lifetime, suggesting this sample may be at relatively greater risk of experiencing mental health problems. First, participants completed the Structured Clinical Interview for DSM-5 (SCID-5) to assess for BPD, other psychopathology, and trauma exposure. Participants also completed a battery of self-report questionnaires, including measures of risky behavior (Risky, Impulsive, and Self-destructive behavior Questionnaire; Sadeh & Baskin-Sommers, 2017). Second, participants completed a neuroimaging protocol that involved both structural and functional magnetic resonance imaging (MRI). Following a standard preprocessing pipeline that included spatial smoothing of 15 FWHM, FreeSurfer’s QDEC application was used to calculate cortical thickness estimates, with age and gender entered as covariates, and BPD symptoms entered as a continuous factor. The vertex-wise significance threshold was set at p < 0.005 and Monte Carlo simulations (10000 iterations) were used to correct for multiple comparisons, resulting in a whole-brain-corrected threshold of p < 0.05. Only regions surviving correction for multiple comparisons are reported.

Results: In the whole-brain analysis, BPD severity correlated negatively with cortical thickness in a cluster centering on the right orbitofrontal cortex (OFC), indicating that greater BPD psychopathology was associated with less cortical thickness in this region. Discussion: This study provides evidence that BPD severity in a diverse community sample correlates with cortical thickness in the OFC, a region of the prefrontal cortex that is directly involved in executive functioning, and notably emotion-based decision-making. Further work will investigate whether thickness in this brain region is associated with other relevant clinical correlates, including risky behavior and lifetime trauma exposure.