Borderline personality disorder and comorbid addiction: epidemiology and treatment.

Background: Borderline personality disorder (BPD) affects 2.7% of adults. About 78% of adults with BPD also develop a substance-related disorder or addiction at some time in their lives. These persons are more impulsive and clinically less stable than BPD patients without substance dependency. They display suicidal behavior to a greater extent, drop out of treatment more often, and have shorter abstinence phases. The combination of borderline personality disorder with addiction requires a special therapeutic approach.

Method: This review is based on a selective literature search about the treatment of patients with BPD and addiction, with particular attention to Cochrane Reviews and randomized controlled trials (RCT).

Results: The available evidence is scant. In two RCTs, Dialectical Behavior Therapy for Substance Use Disorders (DBT-SUD) was found to improve patients' overall functional level (standardized mean difference, 1.07-1.78) and to increase the number of abstinence days (effect strength [ES], 1.03) and negative urine samples (ES, 0.75). Dual focus schema therapy (DFST) was evaluated in three RCTs. Because of methodological problems, however, no useful quantitative comparison across trials is possible. In one RCT, dynamic deconstructive psychotherapy (DDP) was found to have only a moderate, statistically insignificant effect. Only a single study provides data about potentially helpful drug therapy over the intermediate term.

Conclusion: Patients with borderline personality disorder and comorbid addiction should be treated as early as possible for both conditions in a thematically hierarchical manner. There is no evidence for any restriction on drug therapy to prevent recurrent addiction in these patients. The psychotherapeutic techniques that can be used (despite the currently inadequate evidence base) include DBT-SUD, DFST, and DDP. These patients need qualified expert counseling in choosing a suitable type of psychotherapy. Specific treatment is available in only a few places, and the relevant treatment networks in Germany are just beginning to be constructed.