Introduction: Anxiety disorders are a frequent in borderline personality disorder (BPD) and are associated with more severe symptomatology and poorer functional outcomes. Their presence in BPD is also believed to be the consequence of early life adversities. The aim of our study was to examine the relationship between comorbid anxiety disorders, childhood maltreatment and severity of BPD. Methods: 388 BPD outpatients were assessed for lifetime anxiety disorders and history of childhood maltreatment. Severity of BPD was measured by the number of DSM-IV BPD criteria, history of suicide attempts, hospitalizations, psychotic symptoms, comorbid substance use disorder, other comorbid disorders, level of depression, hopelessness, impulsivity and trait anger. We used logistic regressions to test the association between childhood maltreatment and anxiety disorders and the effect of those factors on severity indicators. Results: More than half of the participants suffered from two or more anxiety disorders. The most common comorbidity was social phobia. Childhood maltreatment was associated with an increased number of anxiety disorders. Both anxiety disorders and childhood maltreatment had, independently from one another, an effect on severity indicators. Anxiety disorders were significantly associated with the number of DSM-IV BPD criteria, suicide attempts and psychotic symptoms. Anxiety disorders had an impact on the level of depression and hopelessness, whereas childhood maltreatment impacted impulsivity and anger trait. Conclusion: Our results show the importance of comorbid anxiety disorders in BPD, as well as their impact on severity. Anxiety disorders and childhood maltreatment should be considered by healthcare professionals to ensure optimal care. Furthermore, interventions targeting those issues need to be developed.

Introduction

Borderline Personality Disorder (BPD) is a fairly common psychiatric disorder. About 2 % of the general population is diagnosed with BPD. In clinical populations, BPD is the most common personality disorder, with a prevalence of 10% of psychiatric outpatients and 20% of psychiatric inpatients (Korzekwa et al., 2008; Leichsenring et al., 2011; Skodol et al., 2002a; Tomko et al., 2014). BPD is a serious mental disorder associated with severe behavioural and emotional dysregulation, severe functional impairment, a high rate of comorbid mental disorders, a high rate of suicide, and substantial costs to society (Leichsenring et al., 2011; Lieb et al., 2004; Oldham, 2006; Skodol et al., 2002; Winsper et al., 2016). The literature indicates a high rate of comorbid mental disorders in BPD, with increased odds of major depressive disorders, anxiety disorders, post-traumatic stress disorders, substance use disorders and eating disorders (Skodol et al., 2002b; Winsper et al., 2016; Zimmerman and Mattia, 1999).