The Neurobiology and Genetics of Borderline Personality Disorder

The diagnosis of borderline personality disorder undoubtedly includes a heterogeneous group of disorders. In fact the diagnosis itself was developed without field trials for validation, and it is therefore not surprising that the agreement using different diagnostic tools is actually quite low (52%) (Kavoussi et al, 1990). Because of the lack of clarity in the phenomenology of the diagnosis, neurobiologic research has been more productive when focusing on tempermental dimensions of the diagnosis (Siever & Davis, 1991). The principal dimensions that have been the focus of biological research into borderline pathology include impulsive aggression and affective instability (Koenigsberg et al, 2001). A factor analysis of DSM-III-R criteria for borderline personality disorder suggests that impulsivity and affective instability formed two of three homogeneous factors underlying the disorder; a third “relatedness” factor was also identified. (Sanislow et al, 2000). While these symptoms are seen across personality disorders, they predominate in the Cluster B personality disorders.