Amygdala-prefrontal disconnection in borderline personality disorder

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Abnormal fronto-amygdala circuitry is associated with impulsive aggression, a key feature of borderline personality disorder (BPD).
• Understanding these neural circuitries is crucial for developing targeted treatments for BPD.

Purpose of the Study:

• To investigate the relationship between prefrontal cortex (PFC) and amygdala metabolic activity in individuals with impulsive aggressive (IED)-BPD compared to controls.
• To examine resting-state and drug-induced (m-CPP) metabolic differences in fronto-amygdala circuitry.

Main Methods:

• Positron emission tomography (PET) with (18)fluorodeoxyglucose (FDG) was used to measure relative glucose metabolic rate (rGMR).
• 26 IED-BPD patients and 24 controls underwent PET scans at rest and after m-CPP administration.
• MRI scans were used to co-register PET data and delineate PFC and amygdala regions.

Main Results:

• Healthy controls exhibited significant positive correlations between right orbitofrontal cortex (OFC) and ventral amygdala metabolism.
• IED-BPD patients showed weaker correlations between the anterior PFC and amygdala, lacking dorsoventral specificity.
• No significant group differences were observed in amygdala volume or overall metabolism, either at rest or after m-CPP.

Conclusions:

• Healthy individuals display a distinct, coupled metabolic activity between the right OFC and ventral amygdala, highlighting dorsoventral amygdala circuitry.
• This specific fronto-amygdala metabolic coupling is absent in individuals with IED-BPD, suggesting a neural basis for their impulsive aggression.