The role of DSM-5 borderline personality symptomatology and traits in the link between childhood trauma and suicidal risk in psychiatric patients

Background: Childhood traumas appear to be linked to suicidal behavior. However, the factors that mediate between these two phenomena are not sufficiently understood. Recent findings suggest that borderline personality disorder (BPD) may explain some of the association. Method: The present study investigated the potential mediating role of BPD symptomatology and traits between reported childhood trauma and suicidal risk in adult psychiatric outpatients (N = 124). BPD symptomatology was measured with DSM-5 Section II criterion-counts (SCID-II; Structured Clinical Interview for DSM-IV Axis II), whereas BPD traits were measured with specified DSM-5 Section III traits (PID-5; Personality Inventory for DSM-5). Childhood traumas were self-reported (CTQ; Childhood Trauma Questionnaire), whereas level of suicidal risk was measured with a structured interview (MINI Suicidality Module; Mini International Neuropsychiatric Interview). Mediation effects were tested by bias-corrected (10.000 boot-strapped samples) confidence intervals. Results: BPD features account for a considerable part of the cross-sectional association between childhood trauma and level of suicidal risk, even when controlling for the influence of gender, age, and educational level. This finding remained stable when testing the model without the suicidality-related BPD criterion and PID-5 items. DSM-5 Section II BPD criterion-counts explained 67% of the total effect, whereas DSM-5 Section III BPD traits accounted for 82% of the total effect. The specific DSM-5 Section III trait facets of "Depressivity" (52%) and "Perceptual Dysregulation" (37%) accounted for most of this effect. Conclusions: The findings provide preliminary support for the proposed mediation model indicating that BPD features may help explain relations between childhood trauma and elevated suicidal risk in adult life, in particular for DSM-5 Section III personality traits of depressivity (e.g., pessimism, guilt, and shame) and perceptual dysregulation (e.g., dissociation). To reduce the suicidal risk among those with a history of childhood trauma, BPD features (including "Depressivity" and "Perceptual Dysregulation") might be an important target of assessment, risk management, and treatment. However, other factors are likely to be involved, and a longitudinal and more large-scale design is warranted for a conclusive test of mediation.