Abstract
The current study examined the temporal precedence of change in obsessive-compulsive symptoms and change in depressive symptoms during the course of an Exposure and Response Prevention (ERP) for pediatric OCD. Participants included 142 children and adolescents (7-17 years; mean age = 12.39, SD = 2.92; 51.40% female; 60.40% Non-Hispanic White) with a primary or co-primary diagnosis of OCD who received ERP in a two-site randomized controlled trial on d-cycloserine augmentation of CBT for pediatric OCD. Participants completed clinician-administered assessments of OC symptoms (Children's Yale-Brown Obsessive Compulsive Scale) and depressive symptoms (Children's Depression Rating Scale-Revised) from baseline to post-treatment follow-up. Lagged mediational analyses did not yield evidence in support of a mediating role for the change in OC symptoms in the effect of ERP on the change in depressive symptoms. In contrast, change in depressive symptoms mediated the effect of ERP treatment on the subsequent change in OC symptoms (95% confidence interval for indirect effect = -0.04 to -0.001), though the effect size was small. Controlling for the prior levels of the depressive symptoms this indirect effect became non-significant. Theoretical and clinical implications of the findings for the youth with OCD and comorbid depression are discussed.