Brain Functional Connectivity Correlates of Subclinical Obsessive-Compulsive Symptoms in Healthy Children

Subclinical obsessive-compulsive (OC) symptoms are fairly common among the general population, with an estimated prevalence between 13% and 28% in adults and around 8% in children without a diagnosis of a mental health disorder.1,2 Although these values contrast with a much lower incidence of clinical obsessive-compulsive disorder (OCD), estimated to be between 1% and 3%,3 there is evidence to suggest that subclinical OC symptoms precede OCD in a significant percentage of patients4 and, more specifically, that the presence of obsessions and compulsions in children increases the likelihood of meeting diagnostic criteria for OCD in adulthood.1,2 Commonly observed subclinical obsessive-compulsive symptoms in healthy children may predispose to obsessive-compulsive disorder (OCD). Therefore, investigating the underlying neurobiology may be relevant to identify alterations in specific brain circuits potentially accounting for clinical heterogeneity in OCD without the confounding effects of clinical samples. We analyzed the brain correlates of different obsessive-compulsive symptoms in a large group of healthy children using functional connectivity measures. We evaluated 227 healthy children (52% girls; mean [SD] age 9.71 [0.86] years; range, 8–12.1 years). Participants underwent clinical assessment with the Obsessive-Compulsive Inventory–Child Version and a resting-state functional magnetic resonance imaging examination. Total and symptom-specific severity were correlated with voxelwise global functional connectivity degree values. Significant clusters were then used as seeds of interest in seed-to-voxel analyses. Modulating effects of age and sex were also assessed. Global functional connectivity of the left ventral putamen and medial dorsal thalamus correlated negatively with total obsessive-compulsive symptom severity. Seed-to-voxel analyses revealed specific negative correlations from these clusters with limbic, sensorimotor, and insular regions in association with obsessing, ordering, and doubt-checking symptoms, respectively. Hoarding symptoms were associated with negative correlations between the left medial dorsal thalamus and a widespread pattern of regions, with such associations modulated by sex and age. Our findings concur with prevailing neurobiological models of OCD on the importance of cortico-striato-thalamo-cortical dysfunction to account for symptom severity. Notably, we showed that changes in cortico-striato-thalamo-cortical connectivity are p