Affective dysregulation and dissociative experience in female patients with borderline personality disorder: a startle response study

Affective dysregulation and dissociation are currently discussed as core features of borderline personality disorder (BPD). Affective dysregulation is hypothesized to be correlated with increased amygdala functioning and dissociation is linked to inhibited processing on the amygdala and dampened autonomic output, according to the corticolimbic disconnection model of dissociation from Sierra and Berrios [Biological Psychiatry 44 (1998) 898]. We assessed startle response, which is mainly mediated by the amygdala, to investigate the relationship between affective dysregulation and dissociation. We hypothesized that patients with BPD would reveal enhanced responses to startling tones, but that these would be lessened by the presence of state dissociative experiences. 21 unmedicated female patients with BPD and 21 healthy female controls listened to 15 startling tones (95-dB, 500-ms, 1000-Hz) while heart rate, skin conductance and orbicularis oculi electromyogram responses were measured. Covariance analysis showed that the BPD group had a significantly higher startle response in the electromyogram as compared to controls. Furthermore, present-state dissociative experiences significantly influenced the startle response. Patients with low dissociative experiences revealed enhanced startle responses whereas patients with high dissociative experiences showed reduced responses. Our data support affective dysregulation in BPD as well as the corticolimbic disconnection model of dissociation at least for EMG. Furthermore, it highlights the importance of assessing present-state dissociation in basic research as well as psychotherapy. (C) 2004 Elsevier Ltd. All rights reserved.