Abstract
Borderline personality disorder (BPD) is one of the most commonly experienced personality disorders (Comtois & Carmel, 2016). Dialectical Behavior Therapy (DBT; Linehan, 1993) is an evidence-based psychotherapy shown to be effective in reducing symptoms of BPD (e.g., Linehan, 1993). Researchers have found mixed findings about the effectiveness of DBT with comorbid disorders which is concerning given that BPD frequently co-occurs with other mental health disorders. One comorbid disorder of particular interest is Posttraumatic Stress Disorder (PTSD), which has estimated co-occurrence with BPD between 25–56% (Golier et al., 2003; Mueser et al., 1998; Zanarini et al., 1998). The present study examined how symptoms and consequences of PTSD and related constructs may impact the ability to acquire and implement DBT skills. Participants (N = 108) were recruited from Amazon M-Turk and were given pre-screening measures for BPD. Participants were admitted to the study if they screened positive for probable BPD, and were randomized into one of five treatment conditions (mindfulness, distress tolerance, emotion regulation, interpersonal effectiveness, and positive affirmations). Each intervention used videos teaching them a skill relevant to their treatment condition, then instructed them to practice the skill for one week, and then they completed questionnaires about their experience. While findings did not support unique contributions of PTSD as barriers to DBT skill acquisition and implementation perceived social support was shown to mediate the relationship between positive reactions to disclosure of trauma and greater relationship value.