Objective: The goal of this study was to evaluate whether symptoms are reduced and emotion regulation improves when patients with borderline personality disorder (BPD) receive a 5-week course of inpatient dialectical behavioral therapy (DBT) and if changes in emotion regulation are associated with changes in symptoms.
Methods: Forty-four patients with BPD receiving a 5-week course of DBT in a German psychiatry clinic participated. The short version of the "Borderline Symptom List" (BSL-23) was the patient-reported outcome. To measure emotion regulation, the "Self-Report Measure for the Assessment of Emotion Regulation Skills" (SEK-27) was administered. Wilcoxon tests were performed to evaluate whether pre-post changes in the BSL-23 and SEK-27 reached statistical significance. Effect sizes (d) were calculated and correlations between the pre-post differences for both measures were computed to test associations between changes in emotion regulation and changes in symptoms. Completer (n=33) and intention-to-treat (n=43) analyses were performed.
Results: Symptoms (BSL-23) were reduced and emotion regulation (SEK-27) improved during the 5-week inpatient DBT treatment (completer and intention-to-treat analysis: P<0.001). Effect sizes reached d=0.47 for the BSL-23 and d=0.84 for the SEK-27 in the completer analysis, and d=0.38 for the BSL-23 and d=0.68 for the SEK-27 in the intention-to-treat analysis. Improvements in emotion regulation (SEK-27) were correlated with reductions in symptoms (BSL-23) in both the completer (r=0.54; P=0.001) and the intention-to-treat (r=0.59; P<0.001) analyses.
Conclusions: These findings indicate that a 5-week course of inpatient DBT can effectively reduce symptoms in patients with BPD and that the more patients' emotion regulation improves, the more the patients benefit from the therapy.