BACKGROUND AND OBJECTIVE: Borderline personality disorder which constantly changes the mood, identity and interpersonal relationship is a mental disorder classified in category B. Besides, it leads to behaviors such as drug abuse, impulsive sex and suicide which make more difficult the treatment of these patients. The aim of this study was to report the recovery of a personality problem in a case with borderline personality disorder after the head trauma.

CASE REPORT: The personality signs of a 28-year-old boy who had the full criteria of borderline personality disorder including drug abuse, impulsivity, mood instability, periods of anger and aggression were significantly decreased after hitting. Personality difference and improvement of patient were shown in MMPI test and MRI indicated the structural changes in his brain. He had no problem in 4-year-follow up.

CONCLUSION: This report suggested the personality and behavioral changes after head trauma. MRI results indicated that the recovery is probably caused by the destruction area in the frontal lobe and the anterior temporal lobe (near the hippocampus). Thus the importance of neuropsychological factors should be considered in creating the diagnostic criteria.