Medial prefrontal dysfunction and prolonged amygdala response during instructed fear processing in borderline personality disorder

Abstract

Objectives. Affective dysregulation is a clinical hallmark of borderline personality disorder (BPD). This study used an instructed fear task combined with functional MRI (fMRI) and skin conductance response (SCR) to test hypotheses about mechanisms of disturbed fronto-limbic neural circuitry underlying dysfunctional emotional processing in BPD. Methods. Female BPD patients and matched control subjects were exposed to two visual stimuli during fMRI scanning and SCR recording. Subjects were instructed shortly before scanning that one stimulus (Threat) potentially represents an aversive event whereas another stimulus (Safe) represents safety. The aversive event (electrodermal stimulation) itself was only experienced before this instruction and never occurred during fMRI scanning. Results. Both groups showed stronger SCR to Threat compared to Safe indicating differential fear response which habituated over time. BPD compared to control subjects did not show fMRI signal decrease of amygdala activity or relative ventromedial prefrontal cortex (vmPFC) activity increase over time. Moreover, BPD patients showed increased connectivity of the amygdala with vmPFC but decreased connectivity of subgenual ACC with dorsal ACC compared to control subjects. Conclusions. Prolonged amygdala response and a functional disconnection between ventral and dorsal mPFC regions may be part of the neural mechanisms underlying emotional dysregulation in BPD patients.

Key words::

• Borderline personality disorder (BPD)
• fMRI
• instructed fear
• amygdala
• vmPFC

Acknowledgments

We like to thank the Freiburg Brain Imaging Center for continuous support and Dr A. Mobascher and Dipl.-Psych. A. Sebastian for helpful comments on the manuscript. This study was supported in part by the German Research Foundation (DFG) (JA 1785/1-1) to GAJ, LTvE, KL and OT, a NIMH Grant (5-P50MH58911) to DS and a fellowship grant of the Freiburg University Medical School to OT.

Statement of Interest

None to declare.