Exaggerated affect-modulated startle during unpleasant stimuli in borderline personality disorder

Background: Excessive emotional responding is considered to be a hallmark of borderline personality disorder (BPD). The affect-modulated startle response is a reliable indicator of emotional processing of stimuli. The aim of this study was to examine emotional processing in BPD patients (n = 27) and healthy control subjects (n = 21). Methods: Participants viewed an intermixed series of unpleasant, borderline-salient (e.g., "hate"), and neutral (e.g., "view") words and were instructed to think about the meaning of the word for them personally while eyeblink responses were assessed. Results: The BPD patients exhibited larger startle eyeblink during unpleasant but not neutral words, indicating exaggerated physiological affect. This finding remained significant when we controlled for comorbid diagnoses, including generalized anxiety disorder and posttraumatic stress disorder. Greater symptom severity was associated with greater affective-startle difference scores (unpleasant-neutral). Conclusions: Consistent with the symptom of affective clysregulation, these results suggest an abnormality in the processing of unpleasant emotional stimuli by BPD patients.