Finally, given the relative rarity of autoimmune conditions in both the general population and in children with OCD, our data are limited by small sample sizes and low power to detect small differences between subgroups, including OCD-affected and nonaffected first-degree relatives. Nevertheless, our study is the first to carefully consider published population rates and is the largest descriptive study of immune-related comorbidities in childhood-onset OCD. These limitations, most present in previous smaller studies, highlight the need for further data in both general OCD and PANS/PANDAS populations that includes healthy controls together with means of verifying comorbidity diagnoses.
