Many studies have focused on investigating the physiological characteristics and the neurobiology of borderline patients in attempt to relate these symptoms with the purely psychological characteristics.
A study with 30 young women with Borderline personality disorder that used structural magnetic resonance imaging (3D-MRI) showed that the borderline patients had significantly smaller hippocampus (-17%) and a smaller right parietal cortex (-11%) than the control group. This significantly leftward asymmetry in borderline patients was associated with stronger psychotic symptoms and some signs of schizoid personality traits while the smaller hippocampal size was related to trauma-related clinical symptoms and neuropsychological deficits (Irlea E, 2005).
Another study of 21 female borderline patients and a similar group of healthy control subjects took magnetic resonance imaging volumetric measurements of subjects’ hippocampus, amygdala, temporal lobes and prosencephalon. The results showed that patients with BPD had approximately 16% smaller hippocampus and about 8% smaller volumes of the amygdala (Driessen M, 2000).
Studies show that suicide victims, that are often borderline personality patients, have certain neurobiological abnormalities and hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA-axis) (Lopez JF, 1997). Also, it has been discussed that severe anxiety associated with elevated corticotrophin-releasing factor is related to suicidal tendencies and depression (Fawcett J, 1997) that are traits of Borderline personality disorder.