Objective Personal supporters of individuals with borderline personality disorder (BPD) can experience high levels of distress associated with their caregiving role. Previous research focused on other serious mental problems has highlighted the role of modifiable psychological factors in understanding this distress, including caregiver appraisals, expressed emotion and psychological flexibility. This study examines the impact of these predictors for BPD caregivers. Method Using a cross-sectional design, 163 supporters of people with BPD participated in a survey, passed attention checks and met inclusion criteria. Participants completed measures of psychological distress, wellbeing, caregiver appraisal, expressed emotion, and psychological flexibility. Results Regression showed that psychological flexibility was the strongest predictor of caregiver distress (beta = -.49, p < .001) and wellbeing (beta = .44, p < .001), with negative caregiver appraisals and expressed emotion also emerging as significant predictors, although with weaker associations. Psychological flexibility was not found to have a moderating effect on the relationship between expressed emotion and caregiver distress. Conclusions Multiple modifiable factors related to BPD caregiver distress and wellbeing were identified in this study. This research provides initial, cross-sectional, evidence to suggest that interventions that increase psychological flexibility, such as Acceptance and Commitment Therapy, reduce negative caregiver appraisals, and reduce expressed emotion may help to improve the experience of BPD caregivers.
