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

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