title: Borderline personality disorder, impulsivity, and the orbitofrontal cortex.
abstract: OBJECTIVE
  Orbitofrontal cortex lesions produce disinhibited or socially inappropriate behavior and emotional irregularities. Characteristics of borderline personality disorder include impulsivity and affective instability. The authors investigated whether aspects of borderline personality disorder, in particular impulsivity, are associated with orbitofrontal cortex dysfunction.
  
  
  METHODS
  Measures of personality, emotion, impulsivity, time perception, sensitivity to reinforcers, and spatial working memory were administered to patients with borderline personality disorder (N=19), patients with orbitofrontal cortex lesions (N=23), patients with lesions in the prefrontal cortex but not in the orbitofrontal cortex (N=20), and healthy comparison subjects (N=39).
  
  
  RESULTS
  The patients with orbitofrontal cortex lesions and the patients with borderline personality disorder performed similarly on several measures. Both groups were more impulsive and reported more inappropriate behaviors, borderline personality disorder characteristics, and anger and less happiness than the two comparison groups, and both groups were less open to experience and had a faster perception of time (underproduced time) than the healthy comparison subjects. The patients with orbitofrontal cortex lesions and the borderline personality disorder patients performed differently on other measures. The borderline personality disorder patients were less extraverted and conscientious and more neurotic and emotional than all other groups. Patients with orbitofrontal cortex lesions had deficits in reversing stimulus-reinforcer associations and a faster perception of time (overestimated time) than the healthy comparison subjects.
  
  
  CONCLUSIONS
  Orbitofrontal cortex dysfunction may contribute to some core characteristics of borderline personality disorder, in particular impulsivity. Other characteristics of borderline personality disorder, such as high levels of emotionality and personality irregularities, do not appear to be related to the type of dysfunction produced by orbitofrontal cortex damage. The similarities and differences found between the borderline personality disorder patients and the patients with orbitofrontal cortex lesions may lead to a better understanding of the etiology of borderline personality disorder and the functions of the orbitofrontal cortex.
authors.affiliation: Department of Experimental Psychology, University of Oxford. hberlin@post.harvard.edu
authors.forename: Heather A
authors.initials: HA
authors.lastname: Berlin
authors.forename: Edmund T
authors.initials: ET
authors.lastname: Rolls
authors.forename: Susan D
authors.initials: SD
authors.lastname: Iversen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000679:Amygdala / Q000503:physiopathology; D001883:Borderline Personality Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D001927:Brain Diseases / Q000175:diagnosis / Q000503:physiopathology; D015897:Comorbidity; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D007175:Impulsive Behavior / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010552:Personality Assessment; D010554:Personality Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D010555:Personality Inventory; D017397:Prefrontal Cortex / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D011795:Surveys and Questionnaires