Psychotic vulnerability in pediatric obsessive-compulsive disorder: associations with clinical features and treatment outcome in two clinical samples.

Children and adolescents with obsessive-compulsive disorder (OCD) are at increased risk of psychotic disorders; however, the manifestations and clinical implications of psychotic vulnerability among youth with OCD remain poorly understood. To address this gap, we examined the prevalence and clinical correlates of psychotic vulnerability in youth with OCD across two independent samples. Using the Thought Problems Scale of the Child Behavior Checklist (CBCL), we assessed 215 Scandinavian and 125 North American children and adolescents with OCD. Participants with and without psychotic vulnerability were compared in terms of several clinical features, assessed before and after cognitive-behavioral therapy (CBT). We examined whether psychotic vulnerability predicted outcome of CBT. Psychotic vulnerability was identified in 41.6% of the Scandinavian and 34.4% of the North American sample. In both samples, participants with psychotic vulnerability had poorer psychosocial functioning and more depressive symptoms at baseline. In the Scandinavian sample those with psychotic vulnerability had poorer psychosocial functioning and more severe anxiety symptoms post-treatment. In the Scandinavian sample, psychotic vulnerability was linked to the symmetry/hoarding dimension, while in the North American sample it was linked to the ordering and contamination-cleaning dimensions at baseline, and only to the contamination-cleaning dimension after treatment. Importantly, psychotic vulnerability did not predict CBT outcome in any of the samples. Our findings show that an in-depth second-level assessment of psychosis risk is merited in many cases of youth with OCD and suggest that treatment gains following CBT for pediatric OCD are similar in those with and without psychotic vulnerability.