Characterizing the mental health concerns of significant others of those with Borderline Personality Disorder (BPD) and how BPD impacts them

Introduction: Borderline personality disorder (BPD) is a serious psychiatric condition characterized by emotional, interpersonal, and behavioral dysregulation. Significant others (SOs: family member, romantic partner, friend) of those with BPD also endorse elevated mental health concerns. The general severity of BPD symptoms, and/or severity of specific BPD dysregulation components (i.e., emotional, interpersonal, or behavioral) may uniquely influence distinct SO mental health concerns. However, which specific mental health concerns are experienced by SOs of those with BPD, and whether and how BPD influences them, remains unknown. This study therefore aimed to: (1) characterize the mental health concerns (i.e., depression, anxiety, trauma exposure and posttraumatic stress disorder, objective and subjective burden, behavioral dysregulation) of SOs of those with BPD; and (2) clarify whether and how overall BPD symptom severity, and specific BPD dysregulation components, are associated with these SO mental health concerns. Methods: SOs of those with BPD (N = 46) completed measures of mental health concerns, and informant-reports of their loved one with BPD's symptom severity at baseline, 1-, and 2-month follow-ups. Results: SOs exhibited low psychopathology across all mental health concerns, except anxiety severity, which was moderate. Higher overall BPD symptom severity, emotion dysregulation, and behavioral dysregulation, but not interpersonal dysregulation, in the person with BPD predicted worse SO mental health concerns. Discussion: Behavioral and emotional BPD symptom domains may be particularly deleterious to SO mental health, and BPD treatment providers may wish to consider referrals for SO mental healthcare in such instances.