Psychotherapy has been shown to be effective for individuals with body dysmorphic disorder (BDD); however, time to treatment response for different treatments have not yet been examined. We randomized 120 patients to either weekly cognitive behavioral therapy (CBT) or supportive psychotherapy (SPT) at two academic medical research centers. In this secondary data analysis, we aimed to determine the time to first response (30% or greater reduction in BDD symptom severity) in both treatment conditions among those who attended at least one post-baseline assessment (n = 109). As previously reported, CBT for BDD was associated with more consistent improvement in symptom severity and quality of life than SPT. In a pooled analysis combining both sites, the median time to first response was shorter for CBT (76 days [10.9 weeks], 95% CI: 76-107 days) than for SPT (88 days [12.6 weeks], 95% CI: 88-nonestimable days; Χ2df=1 = 3.85, p = .0498). For CBT, the estimated 75th percentile response times were 148 days [21.1 weeks] at site 1 and 134 days [19.1 weeks] at site 2. Response times were not estimable for SPT at either site because the response rate was too low. Thus, therapy clients seeking treatment for BDD and clinicians should be aware that an initial treatment response requires more than 11 therapy sessions for the majority of clients, and that 21 or even more sessions may be required. Treatment response is likely to occur earlier with CBT for BDD (the first-line therapy for BDD) than with supportive psychotherapy.
Keywords: Body Dysmorphic Disorder; cognitive behavioral therapy; supportive psychotherapy; treatment expectation; treatment length.
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