In prior posts, we have discussed the various components of dialectical behavior therapy (DBT). Additionally, we have provided evidence that DBT is an empirically supported treatment (EST) for borderline personality disorder (BPD), bulimia nervosa (BN), and binge eating disorder (BED). The growing mountain of evidence supporting the efficacy and effectiveness of BPD in clinical settings is compelling, but weaknesses still remain in that literature. In particular, the studies examining the use of DBT in eating disordered populations has, in large part, utilized small samples that require additional studies in order to ensure that the findings were not spurious. In a study just published in Eating Disorders: The Journal of Treatment and Prevention, Ben-Porath, Wisniewski, and Warren (2009) provided such additional evidence. Today, I will review their findings and explain how they add to our knowledge regarding the use of DBT in the treatment of eating disorders.
In explaining the rationale for their study, Ben-Porath and colleagues (2009) pointed out that, although the percentage of eating disordered clients who also meet criteria for BPD is unclear, this subgroup is amongst the most difficult eating disordered patients to treat (Johnson, Tobin, & Enright, 1989). To be fair, several of the studies examining the treatment of clients with comorbid BPD and an eating disorder were conducted before DBT had been established as an EST for BPD. In other words, several authors found that BPD predicted significantly worse outcomes in individuals with an eating disorder at a time when we did not yet understand how to treat BPD. For instance, Johnson, Tobin, and Dennis (1990) found that ED patients responded to treatment significantly better than patients with both an eating disorder and BPD. It seems fairly intuitive to assume that, prior to the development of an effective treatment for BPD, the presence of BPD would predict worse outcomes.
The authors of the current study also pointed out that prior studies had found that individuals diagnosed with both an eating disorder and BPD reported greater levels of overall distress and more severe eating disorder symptoms (Wonderlich, Fullerton, Swift, and Kelin, 1994). As such, it appears reasonable to ensure that treatments utilized on this population are truly suitable for this particular cluster of symptoms, as the increased severity of their presentation could theoretically impede recovery.
In this particular study, the authors sought to address this issue by implementing "DBT-informed" treatment for a group of individuals with only an eating disorder as well as a group of individuals diagnosed with both an eating disorder and BPD. 40 participants (1 male, 39 females) participated in a 30 hours per week outpatient program that specifically addresses eating disorders. Eating disorder diagnoses were determined using a semi-structured clinical interview - the gold standard diagnostic procedure. Diagnoses of borderline personality disorder were determined using a combination of a self-report questionnaire and clinician confirmation of diagnosis post-discharge. The diagnostic procedure for BPD was thus less ideal.
The treatment protocol was referred to as "DBT-informed" rather than simply DBT because it involved alterations to the typical DBT approach. Participants took part in twice weekly DBT skills training as well as weekly group sessions involving motivation and commitment, goal setting, and behavioral chain analysis. Participants filled out daily diary cards recording skill usage and participated in weekly yoga and a "DBT-in-action" group that promoted the practice of DBT skills. A nutritional module of treatment taught clients healthy eating practices and in vivo exposure exercises helped participants practice eating feared foods in a manner that allowed their anxiety about such behaviors to diminish. Unlike traditional DBT, individual therapy was not available in this study due to limitations with respect to insurance reimbursement; however, participants were able to meet individually with a clinician for 30 minutes per week to discuss diary cards and therapy interfering behaviors.
The findings from this study are rather impressive. Both groups experienced a significant reduction in eating disorder symptoms from time 1 to time 2, with no difference between groups on the amount of symptom reduction. The length of treatment varied across individuals, an important consideration, however it is nonetheless impressive that the presence of BPD did not diminish symptom reduction. Both groups also experienced significant reductions in depressive and anxiety symptoms. Participants with both an eating disorder and BPD, however, initially presented with higher levels of depression and anxiety. Perhaps most impressively, however, were the authors' findings regarding emotion regulation. At the onset of the study, participants with both an eating disorder and BPD reported being less able to regulate negative emotions than did participants with only an eating disorder. By the end of treatment, however, both groups exhibited significant improvement and there was no difference between the two groups on their ability to regulate negative emotions.
Overall, these findings present an optimistic picture of the prognosis for individuals with an eating disorder and comorbid BPD. DBT skills appear to be highly useful in reducing both eating disorder and personality disorder symptoms, thus further debunking the myths that individuals with BPD can not be treated and that individuals with both an eating disorder and BPD are unlikely to recover from their eating disorders.
Although these findings are promising, a few noteworthy limitations should be mentioned. First, although the number of participants who met criteria for anorexia nervosa (AN) was small (n = 8), the inclusion of AN in the sample somewhat confuses the findings. As discussed previously on PBB, AN responds to different treatment approaches than do BN and BED. In fact, although family-based treatment for children and adolescents with AN has empirical support, the overall response of AN to treatment is significantly worse than is the response to treatment of BN and BED. Importantly, a higher percentage of participants in the eating disorder only group (25%) met criteria for AN than did participants in the eating disorder plus BPD group (7.1%). With fewer treatment resistant individuals in the comorbid group, the treatment responses of the two groups may have been obscured. Additionally, because the length of stay in treatment differed between individuals, it is unclear if length of stay impacted degree of recovery. Also, the "DBT-informed" approach, while explained well in the manuscript, is fairly large in scope, meaning that it may be difficult to implement in general practice. This last point is not a weakness of the study itself, but rather a simple acknowledgment that real world practice quite often struggles to fully implement complex protocols described in empirical articles.
So what is the take-home point of this article? Although more research on the use of DBT in eating disorders in general and BN and BED in particular is necessary, all of the research to date supports this approach as an efficacious treatment. Importantly, such research highlights the pivotal role of emotion regulation in the onset and maintenance of eating disordered behaviors and thus emphasized the need to address emotion regulation skills in therapy. Comorbid diagnoses of an eating disorder and BPD may result in an initial presentation of greater severity, but this does not mean that treatment response will be poor. It simply means that the right therapeutic approach must be utilized and, not surprisingly, the gold standard approach to the treatment BPD appears to be the best method for treating a combination of BPD and an eating disorder.
If you would like to learn more about eating disorders, borderline personality disorder, and dialectical behavior therapy, we recommend the following resources, all of which are available through our online store:
Crave: Why You Binge Eat and How to Stop
Overcoming Binge Eating
Dialectical Behavior Therapy for Binge Eating and Bulimia
Cognitive-Behavioral Treatment of Borderline Personality Disorder
Skills Training Manual for Treating Borderline Personality Disorder
Treating Borderline Personality Disorder: The Dialectical Approach
From Suffering to Freedom: Practicing Reality Acceptance
Crisis Survival Skills: Part One: Distracting and Self-Soothing
Crisis Survival Skills: Part Two: Improving the Moment and Pros and Cons
Opposite Action: Changing Emotions You Want to Change