Prevalence and impact of insomnia in children and adolescents with body dysmorphic disorder undergoing multimodal specialist treatment

Pediatric body dysmorphic disorder (BDD) is challenging to treat. This study aimed to establish the prevalence of insomnia in youth with BDD and explore its impact on clinical outcomes. Sixty-six children and adolescents with BDD consecutively referred to a specialist clinic completed a range of clinical measures, including the Yale-Brown Obsessive–Compulsive Scale Modified for BDD-Adolescent Version (BDD-YBOCS-A), and the Insomnia Severity Index (ISI). Patients with clinical insomnia (ISI score ≥ 9) were compared to the rest of the sample on socio-demographic and clinical features. Fifty-six patients who received multimodal treatment were re-assessed post-treatment. A mixed-model ANOVA was performed to compare treatment outcomes between the insomnia vs. no insomnia groups, and Chi-squared tests were used to compare response and remission rates. According to the ISI, 48% of the sample qualified as having insomnia at baseline. These participants showed significantly higher self-reported BDD symptom severity, more depressive symptoms, and more functional impairment in daily activities. Patients with insomnia improved less on the BDD-YBOCS-A than those without insomnia, although the difference did not reach statistical significance. The rates of responders and remitters were lower in the insomnia group, compared to the non-insomnia group. Insomnia is prevalent in pediatric BDD, and is associated with more severe psychopathology and worse functioning in daily activities. Furthermore, youth experiencing BDD and insomnia may benefit from multimodal treatment to a lesser extent than those without insomnia. If these results are replicated in larger samples, treatment refinements for pediatric BDD could include specific modules to directly target insomnia. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00787-019-01442-1) contains supplementary material, which is available to authorized users.