The Effect of Oxytocin Administration on Interpersonal Cooperation in Borderline Personality Disorder Patients and Healthy Adults

The study will examine behavioral patterns and underlying neural correlates which distinguish patients with borderline personality disorder (BPD) from healthy subjects as they participate in a two-person trust game and will determine whether administration of intranasal oxytocin (OT) will normalize trust game performance and concomitant neural processing in the BPD group.

Inclusion Criteria: * BPD subjects meets criteria for DSM-IV Borderline Personality Disorder. * 18 to 55 years old * Healthy controls are free of any lifetime DSM-IV Axis I or Axis II diagnosis. However, to avoid a group of HC's too highly groomed and unrepresentative of the general population subjects meeting criteria for a past Axis I diagnosis of adjustment, dysthymic, or depressive NOS disorders, specific phobias, and sleep disorders will not be excluded. Subjects will not be excluded for a non-IV substance abuse disorder more than 6 months prior to enrollment. * All subjects will be free of psychotropic medications for 2 weeks (6 weeks for fluoxetine). * Subjects may be enrolled in psychotherapy. Exclusion Criteria: * BPD subjects not meeting DSM-IV criteria for past or present bipolar I disorder, schizophrenia, schizoaffective disorder, substance dependence, head trauma, CNS neurological disease, seizure disorder or current major depression. Since depression is commonly associated with BPD, too stringent a depression exclusion criterion would yield a clinically atypical BPD sample. For this reason, BPD patients with Axis I depressive disorders other than major depression and those with a past history of major depression will not be excluded. * Substance abuse disorder in the prior 6 months * Significant medical illness * Pregnancy * Metallic foreign-bodies that contraindicate MRI