Several randomised clinical trials (RCT) have demonstrated the efficacy of cognitive behavioral therapy in the treatment of Posttraumatic Stress Disorder (PTSD). However, the external validity of these studies is limited with regard to PTSD related to childhood sexual abuse which often results in severe and complex sympomatology accompanied by a variety of concurrent disorders or symptoms, for example self-mutilation, suicidal ideation, or severe dissociation. Nearly 30% of patients with PTSD have a co-occuring borderline personality disorder (BPD). The prevalence rates of PTSD in patients with BPD vary between 40% and 60%.

Several RCTs have shown the efficacy of Dialectical Behavioral Therapy (DBT) in the treatment of borderline patients, who exaggerate severe behavioural dyscontrol. However specific treatment for co-occuring PTSD has been lucking.

Clinical lore suggests that exposure to trauma-relevant memories can potentially aggravate dysfunctional behaviour in patients with BPD. Empirical research however reports discrepant results with two studies documenting deleterious effects of comorbid BPD on treatment outcome, whereas one study did not find an impact.

DBT-P was specifically tailored to treat patients with PTSD after sexual abuse during childhood. DBT-P includes training in emotion regulation and mindfulness, cognitive interventions and exposure elements, usually in combination with the use of skills. To evaluate the efficacy of DBT-P as compared to a wait list control group a RCT is currently carried out. Preliminary data, which will be presented, revealed large between effect sizes for the primary outcome measures (PDS, CAPS).