Elevated T3 levels have been reported in men with antisocial behavior. The aim of the present study was to investigate the relationship between thyroid hormones and expressed adult interpersonal violence in female patients with borderline personality disorder (BPD). Furthermore, expressed adult interpersonal violence in female BPD patients was compared to healthy female controls. A total of 92 clinically euthyroid women with BPD and 57 healthy women were assessed with the Karolinska Interpersonal Violence Scales (KIVS). Baseline thyroid function was evaluated by measuring plasma free and bound triiodothyronine (FT3 and T3), thyroxine (FT4 and T4), and thyroid-stimulating hormone (TSH) with immunoassays in patients. Plasma cortisol was also measured. Among females with BPD, expressed interpersonal violence as an adult showed a significant positive correlation with the T3 levels. The mean expression of interpersonal violence as an adult was significantly higher in BPD patients as compared to healthy controls. The multiple regression model indicated that two independent predictors of KIVS expressed interpersonal violence as an adult: T3 and comorbid diagnosis of alcohol abuse. Association between T3 levels and violent/aggressive behavior earlier reported exclusively in male samples may be valid also in females with BPD.
The risk of violent behavior is elevated in both individuals with personality disorders (Berman et al., 1998, Johnson et al., 2000 and Coid et al., 2006) as well as in the context of hazardous drinking. Borderline personality disorder (BPD) has been associated with violent acts (Fountoulakis et al., 2008), especially if combined with antisocial personality disorder (Howard et al., 2008 and Látalová and Praško, 2010), even though the association may not be that evident in all groups of BPD patients (Allen and Links, 2012). Impulsive aggression, a heritable trait (Olweus, 1979 and Coccaro et al., 1993), is a core feature of “cluster B” personality disorders, particularly antisocial personality disorders as well as BPD.
Thyroid hormones, in relation to violent behavior, have been studied mostly in male forensic settings. Elevated mean T3 levels have been reported in young criminally active and institutionalized male recidivists, as compared to non-delinquent controls, although the two groups did not differ in TSH levels (Levander et al., 1987). In line with that finding, young men with persistent criminal behavior had higher mean T3 levels, as compared to both men with previous but no current antisocial behaviors and controls (Alm et al., 1996). In addition, Stålenheim (2004) found positive associations between T3 levels and Psychopathic Check List scores of Detachment and Irritability, in a group of violent male criminal recidivists. Suicidal and violent behaviors are interlinked and may share common neurobiological underpinnings. We have reported that high scores on aggressiveness were associated with a low T3/T4 ratio in male suicide attempters (Sinai et al., 2009). Stress reactions have also been associated with the thyroid function (Kioukia-Fougia et al., 2002), and basal hypothalamic pituitary adrenal (HPA) axis activity has been reported to be negatively related to provoked aggressive behavior (Böhnke et al., 2010).
No prior study has assessed the association between thyroid hormones and expressed interpersonal violence in women. Studies in the general population have reported that men are more violent than women, but this has not been found to be the case among psychiatric inpatients (Krakowski and Czobor, 2004).
The aim of the present study was to assess the relationship between thyroid hormones and expressed adult interpersonal violence in female patients with borderline personality disorder. Furthermore, we compared expressed adult interpersonal violence in female BPD patients with violence scores of female healthy volunteers. It is not known if the same kind of association between thyroid hormones and violent behavior, earlier reported in antisocial male populations, could be found in women with BPD and severe suicidal behavior. We hypothesized higher scores of expressed interpersonal violence in individuals with BPD, and that thyroid hormones and comorbid substance abuse would be associated with adult violent behavior in patients with BPD.
