Impact of sleep disruption on BDD symptoms and treatment response

Background: Body dysmorphic disorder (BDD) is severe, undertreated, and relatively common. Although goldstandard cognitive behavioral therapy (CBT) for BDD has strong empirical support, a significant number of patients do not respond. More work is needed to understand BDD's etiology and modifiable barriers to treatment response. Given its high prevalence and impact on the development, maintenance, and treatment of related, frequently comorbid disorders, sleep disruption is a compelling, but not-yet studied factor. Methods: Data were drawn from a randomized controlled trial of guided smartphone app-based CBT for BDD. Included participants were offered 12-weeks of treatment, immediately (n = 40) or after a 12-week waitlist (n = 37). Sleep disruption and BDD symptom severity were assessed at baseline, week-6, and week-12. Results: Hypotheses and analysis plan were pre-registered. Two-thirds of patients reported significant insomnia symptoms at baseline. Baseline severity of sleep disruption and BDD symptoms were not related (r = 0.02). Pretreatment sleep disruption did not predict BDD symptom reduction across treatment, nor did early sleep improvements predict greater BDD symptom improvement. Early BDD symptom improvement also did not predict later improvements in sleep. Limitations: Limitations include the small sample, restricted ranges of BDD symptom severity and treatment response, and few metrics of sleep disruption. Conclusions: Although insomnia was disproportionately high in this sample and both BDD symptoms and sleep improved in treatment, results suggest sleep and BDD symptoms may function largely independent of one another. More work is encouraged to replicate and better understand findings as well as potential challenges and benefits of addressing sleep in BDD.