Background: Neuropsychological and imaging studies of patients with antisocial (ASPD) and borderline personality disorder (BPD) are suggestive of frontal lobe dysfunction in these individuals. In normal subjects functional brain imaging has been used to investigate the neuroanatomy of impulse control. There are no such imaging studies in personality-disordered populations.
Aim: This study aimed to investigate which neuronal networks are involved in response inhibition in Cluster B personality disorders and whether these are different from healthy subjects.
Hypothesis: We hypothesized that the personality-disordered sample would have attenuated orbitofrontal cortex responses during performance of a Go/NoGo task compared with healthy controls.
Method: Eight inpatients with a DSM-IV diagnosis of borderline or antisocial personality disorder and eight healthy controls were scanned using fMRI while performing a Go/NoGo task. Impulsivity was assessed using the Barratt Impulsivity Scale (BIS) and the Impulsiveness-Venturesomeness-Empathy (IVE) inventory.
Results: In the control group the main focus of activation during response inhibition was in the prefrontal cortex, specifically the right dorsolateral and the left orbitofrontal cortex. Active regions in the patient group showed a more bilateral and extended pattern of activation across the medial, superior and inferior frontal gyri extending to the anterior cingulate.
Conclusions: fMRI is a useful tool to detect brain activation during response inhibition. ASPD and BPD patients activate different neural networks to successfully inhibit pre-potent responses.