Predictors and Moderators of Response to Cognitive-Behavioral Therapy for Body Dysmorphic Disorder (BDD)

August 3, 2022

Ruta Nonacs, MD PhD

Greater motivation and readiness to change and greater treatment expectancy were predictors of treatment response.

Body dysmorphic disorder (BDD) is a psychiatric disorder consisting of distressing or disabling preoccupations related to nonexistent or slight defects in appearance, combined with repetitive behaviors performed in response to these concerns about one’s appearance — for example, checking the mirror repeatedly or excessive grooming. BDD is often associated with significant functional impairment and poor quality of life, as well as increased risk of attempted and completed suicide.

Multiple studies support the use of cognitive behavioral therapy (CBT) for the treatment of BDD. A previous study from Hilary Weingarden, PhD and her colleagues from the Center for OCD and Related Disorders (CORD) demonstrated that 52% of patients receiving 24 weeks of therapist-delivered CBT experienced a sustained remission of their symptoms at six months after treatment completion, as compared to 27% in participants receiving supportive psychotherapy. In this study, remission was never achieved by 18% in the CBT group and 45% in the SPT group.

Predictors and Moderators of Response to CBT for BDD

While there is data to support the use of CBT for the treatment of BDD, our understanding of the factors which predict and moderate treatment outcomes in individuals with BDD is limited. Jennifer Greenberg, PsyD and her colleagues at the Center for OCD and Related Disorders (CORD) at Mass General have examined predictors and moderators of improvement in patients receiving CBT for BDD using data from a randomized controlled trial of 120 individuals receiving either therapist-delivered CBT for BDD or supportive psychotherapy for 24 weeks and a smaller pilot study of CBT for BDD (Greenberg et al, 2019; Phillips et al, 2021).

Greater motivation and readiness to change at baseline was a significant predictor of treatment response. Readiness/motivation to change measured using the University of Rhode Island Change Assessment (URICA): Readiness to Change (RTC) was a particularly powerful predictor; a single unit of increase in the URICA-RTC more than doubled the odds of treatment response.

Greater treatment expectancy (confidence in the treatment) at baseline was also a significant predictor of treatment response.

Severity of BDD symptoms and associated functional impairment did not negatively impact treatment response.

Comorbid depressive symptoms had no impact on treatment response; however, they noted that depressive symptoms may increase risk for dropout.

Minimal early symptom improvement during the first four weeks of treatment was not indicative of eventual non-response. Thus, patients and clinicians should not be discouraged by limited early improvement and should instead continue with a full course of treatment before reevaluating progress and alternative interventions.

Clinical Implications

Understanding how individuals with BDD differentially respond to treatment with CBT will help to determine whether CBT for BDD may be more or less efficacious in a given patient, ultimately allowing clinicians to provide more personalized treatment. CBT for BDD requires a long duration of treatment (typically more than 22 sessions), significant time commitment on a daily basis, and specialized treaters. Being able to identify who is most likely to receive benefit from this intervention alone at the outset of treatment would allow for better allocation of clinical resources.

Further research is necessary to determine if it is possible to improve the likelihood of response and remission in patients receiving CBT. The finding that patients with greater motivation and readiness to change are more likely to receive benefit from CBT raises the question of whether certain pre-treatment strategies could be used to improve treatment adherence and outcomes. For example, before initiating CBT for BDD, efforts to enhance readiness and motivation to change may be particularly helpful. More specifically, patients with low readiness to change, particularly those with poor insight, may benefit from strategies, such as motivational interviewing, which may help to resolve ambivalence and enhance motivation to change.

In addition, the finding that treatment expectancy is a predictor of improvement suggests that educational strategies deployed prior to initiating CBT could improve outcomes. For example, providing patients with data on positive treatment outcomes from prior studies and a compelling rationale for the use of specific CBT treatment elements to address BDD symptoms may increase patients commitment to treatment and may improve treatment outcomes.

Wilhelm and colleagues recently demonstrated the efficacy of a brief (12-week) smartphone-delivered CBT for BDD with coach support in reducing BDD and associated symptoms (2022). App-based treatments are a widely accessible, low-cost, low-stigma resource that are highly flexible, allowing individuals to use CBT skills when, and in the settings, most relevant for them.

While there is a tendency to consider pharmacotherapy with SSRIs or SNRIs as first-line treatment for individuals with severe BDD, these results suggest that even individuals with severe BDD and high levels of functional impairment can be treated successfully with CBT for BDD. In addition, depressive symptoms were not significant predictors of treatment outcomes. Severity of these symptoms and impairment may not affect outcomes; however, the researchers note that because these patients may be at greater risk for dropping out of treatment early, it may be beneficial to employ specific strategies, such as behavioral activation, in addition to motivational enhancement, to ensure adherence and completion of the full course of treatment.