Abnormal prefrontal cortical response during affective processing in borderline personality disorder

Emotion dysregulation is a hallmark feature of borderline personality disorder (BPD) and is associated with a dysfunction of prefrontal (PFC)–limbic systems. The purpose of the present study was to examine PFC function in BPD during the experience and suppression of sadness. Subjects were females with BPD (N = 9) and age-, gender-, and IQ-matched non-psychiatric comparison subjects (N = 8). Evoked hemodynamic oxygenated hemoglobin (oxy-Hb) was examined in PFC using functional near-infrared spectroscopy while subjects viewed neutral or sad images and were instructed to either maintain or suppress their emotional reactions. No group differences in behavioral ratings of sadness suppression or mean levels of evoked oxy-Hb were observed. BPD and control subjects, however, recruited homologous regions of lateral PFC during emotional suppression, with right lateral PFC activation for BPD subjects associated with difficulty suppressing sadness, whereas an inverse relationship was observed in left lateral PFC for healthy controls. Exploratory analyses revealed that the slope of the rise in oxy-Hb in medial PFC during transient sadness was positive and steep for healthy controls. Conversely, BPD subjects showed a negative and shallow slope, which was associated with severity of clinical symptoms. These results suggest that BPD subjects may show abnormal evoked oxy-Hb in medial PFC during transient sadness, with recruitment of right lateral PFC in BPD associated with reported difficulty in suppressing emotion. This abnormal cortical response, possibly in tandem with subcortical–limbic regions, may underlie symptoms of emotion dysregulation in BPD.