1 - (SYM 113) Organizing Borderline Personality Disorder Symptoms, Childhood Maltreatment Experiences, and PTSD Symptoms: Do Unique Subgroups Exist and Influence Dialectical Behaviour Therapy Outcomes?

Borderline Personality Disorder (BPD) involves instability in emotions, behaviours, and relationships. Childhood maltreatment experiences (including trauma) and Posttraumatic Stress Disorder (PTSD) symptoms highly associate with BPD and predict worse BPD treatment responses. Many distinct combinations of childhood maltreatment, PTSD symptoms, and BPD symptoms exist in those with BPD, and these phenomena may co-vary to form distinct subgroups of BPD. Individuals across subgroups may also have unique BPD treatment outcomes, requiring distinct interventions. However, whether such subgroups exist and differentially predict BPD treatment outcomes remains unclear. The present study examined whether those with BPD: 1) exhibit unique subgroups of BPD symptoms, childhood maltreatment experiences, and PTSD symptoms; and 2) have distinct BPD-relevant treatment outcomes (i.e., BPD and PTSD symptom severity, self-injury frequency) based on one’s subgroup when receiving standard Dialectical Behaviour Therapy (DBT). Participants were trauma-exposed adults with BPD (N=192) who endorsed recent, chronic self-injury, and completed measures of childhood maltreatment, PTSD symptoms, and BPD symptoms. Items from these measures were entered into a Latent Profile Analysis (LPA) to identify subgroups. A subsample (N=98) of the LPA sample then underwent 12-months of standard DBT and completed measures of BPD, PTSD, and self-injury at baseline and every three months during and the year after treatment. The LPA identified three subgroups (i.e., Low, Moderate, and High Severity), which stratified based on the severity of childhood maltreatment experiences, PTSD symptoms, and BPD symptoms. Within each subgroup, childhood emotional abuse and neglect, and avoidance and intrusion PTSD symptoms, were higher in severity compared to other childhood maltreatment experiences and PTSD symptoms. Generalized estimating equation models indicated that the Low subgroup exhibited a significantly faster decline in PTSD symptoms, compared to the High subgroup (B = 2.31, SE = .70), and BPD symptoms, compared to Moderate (B = .10, SE = 0.03) and High (B = .18, SE = .04) subgroups. The Moderate subgroup also exhibited a significantly faster decline in BPD symptoms (B = 0.07, SE = .03) and self-injury frequency (B = .22, SE = .10) compared to the High subgroup. Results suggest that higher severity childhood maltreatment experiences and PTSD symptoms may indicate alternative (e.g., trauma-focused) interventions to standard DBT for PTSD, BPD, and self-injury to improve.