Impulsivity, aggression and brain structure in high and low lethality suicide attempters with borderline personality disorder

Abstract

Impulsivity and aggressiveness are trait dispositions associated with the vulnerability to suicidal behavior across diagnoses. They are associated with structural and functional abnormalities in brain networks involved in regulation of mood, impulse and behavior. They are also core characteristics of borderline personality disorder (BPD), a disorder defined, in part, by recurrent suicidal behavior. We assessed the relationships between personality traits, brain structure and lethality of suicide attempts in 51 BPD attempters using multiple regression analyses on structural MRI data. BPD was diagnosed by the Diagnostic Interview for Borderline Patients-revised, impulsivity by the Barratt Impulsiveness Scale (BIS), aggression by the Brown-Goodwin Lifetime History of Aggression (LHA), and high lethality by a score of 4 or more on the Lethality Rating Scale (LRS). Sixteen High Lethality attempters were compared to 35 Low Lethality attempters, with no significant differences noted in gender, co-morbidity, childhood abuse, BIS or LHA scores. Degree of medical lethality (LRS) was negatively related to gray matter volumes across multiple fronto-temporal-limbic regions. Effects of impulsivity and aggression on gray matter volumes discriminated High from Low Lethality attempters and differed markedly within lethality groups. Lethality of suicide attempts in BPD may be related to the mediation of these personality traits by specific neural networks.

Keywords: Borderline personality disorder; Impulsive–aggression; Magnetic resonance imaging; Suicidal behavior.

Fig. 1

In ALL BPD attempters: Significant clusters (p<.05, cluster level) showing a negative association between Lethality Rating Scale scores and grey matter are rendered on a) bilateral lateral cortical surface views, b) ventral view of the cortical surface, and c) successive axial slices (z=−36 to z=20). Significant decreases were observed in Mid-Inf OFC(1), Fusiform(1), Insula(2), Hippocampus (3), Parahippocampus(4), Mid-Inf OFC(5), ACC(6), Lingual(7), Mid-Sup Temp(8)

Fig. 2

Significant clusters (p<.05, cluster level) in High Lethality attempters (RED) and Low Lethality attempters (BLUE) showing a positive association between gray matter and aggression (LHA) are rendered on a) bilateral lateral cortical surface views, b) ventral view of the cortical surface and c) successive axial slices (z=−36 to z=20). Significant associations shown in Fusiform(1), ACC(2), Mid-Inf OFC(3), Insula(4).

Fig. 3. Low Lethality subjects

Significant clusters (p<.05, cluster level) showing a negative association between impulsivity (BIS) and grey matter are rendered on a) bilateral lateral cortical surface views, b) ventral view of the cortical surface and c) successive axial slices (z=−36 to z=20). Significant decreases are shown in : Insula(1), Fusiform(2), Mid-Inf OFC(3), Parahippocampus(4), Hippocampus(5), Lingual(6), Amygdala (7), Mid-Sup Temp(8), ACC(9)