Diagnostically complex Veterans with comorbid PTSD benefit from Dialectical Behavior Therapy: Effects of PTSD on BPD symptom trajectories

Dialectical behavior therapy (DBT) is considered a frontline treatment for reducing suicide behavior among those with borderline personality disorder (BPD) and has been proven effective when delivered within Veterans Health Administration. Much of the research supporting use of DBT has been conducted in homogenous samples, yet Veterans are diagnostically complex. Specifically, given high rates of exposure to trauma, Veterans with BPD are especially likely to have comorbid posttraumatic stress disorder (PTSD). We sought to understand how a PTSD diagnosis affected treatment outcomes of Veterans presenting for full-model DBT treatment. We tested whether comorbid PTSD affected baseline severity, treatment engagement, or treatment outcomes in a sample of 62 Veterans, half of whom had probable or confirmed PTSD. We found that comorbid PTSD did not hamper treatment engagement and was unrelated to BPD symptom severity at baseline. We further found that BPD-PTSD was associated with noninferior and in fact sharper reductions in BPD symptoms over the course of treatment. Altogether, our findings support the use of DBT in diagnostically complex Veterans who present with both BPD symptoms and PTSD.