Connectome-wide Functional Connectivity Abnormalities in Youth With Obsessive-Compulsive Symptoms

The Longitudinal Relationship Between Brain Morphology and Obsessive-Compulsive Symptoms in Children From the General Population

Objective

Cross-sectional studies in children with obsessive-compulsive disorder (OCD) have found larger thalamic volume, which is not found at later ages. We previously found that 9- to 12-year-old children from the general population with clinical-level obsessive-compulsive symptoms (OCS) also have a larger thalamus. Thus, using a longitudinal design, we studied the relationship among thalamic volume, cortical maturation, and the course of OCS.

Method

Children from the population-based Generation R Study underwent 1 or 2 (N = 2,552) magnetic resonance imaging (MRI) scans between the age of 9 and 16 years (baseline 9-12 years, follow-up 13-16 years). OCS were assessed with the Short Obsessive-Compulsive Disorder Screener (SOCS) questionnaire using both continuous and clinical cut-off measures to identify children with "probable OCD." We applied linear regression models to investigate the cross-sectional relationship between brain morphology and OCS at age 13 to 16 years. Linear mixed-effect models were fitted to model the bidirectional longitudinal relationship between thalamus and OCS and the thalamus and cortical morphology.

Results

Thalamic volume was not different between probable OCD cases and controls at age 13 to 16 years. Higher baseline thalamic volume predicted a relative persistence of OCS and a flatter slope of thinning in 12 cortical regions.

Conclusion

Larger thalamic volume may be a subtle biomarker for persistent OCS symptoms. The persistence of OCS and cortical thickness in relation to earlier larger thalamic volume may reflect being at an earlier stage in neurodevelopment. Longitudinal designs with repeated multimodal brain imaging are warranted to improve our understanding of the neurodevelopmental processes underlying OCS and OCD.

Study preregistration information

Relationship between obsessive-compulsive symptoms and brain morphology in school-aged children in the general population; https://osf.io/; y6vs2.

Error-related brain activity associated with obsessive-compulsive symptoms in youth

BACKGROUND

Subclinical obsessive-compulsive symptoms (OCS) are common in children, and increase risk for later onset of obsessive-compulsive disorder (OCD). In pediatric patients with OCD, neuroimaging research implicates altered neural mechanisms for error-processing, but whether abnormal brain response occurs with subclinical OCS remains poorly understood.

METHODS

Using functional magnetic resonance imaging (fMRI), 113 youth (8-18 years; 45 female) from a community sample were scanned during an error-eliciting Go/No-Go task. OCS were assessed dimensionally using the obsessive-compulsive subscale of the Child Behavior Checklist. The association between OCS scores and error-related brain activity was examined at the whole-brain level.

RESULTS

Lower OCS scores associated with stronger response to errors in dorsal anterior cingulate cortex (dACC), caudate, putamen, thalamus, and occipital cortex. Additionally, lower OCS related to higher capacity for inhibitory control, as indexed by greater accuracy on No-Go trials during fMRI scanning. The relationship between lower OCS and better accuracy on No-Go trials was mediated by greater error-related dACC activity.

CONCLUSIONS

The inverse relationship between OCS and error-related activity in the dACC and extended cortical-striatal-thalamic circuitry may index an adaptive process by which subclinical OCS are minimized in youth. Further, these results identify an observable pattern of brain activity that tracks with subclinical OCS severity. Understanding the link between neural networks for error processing and the normal to abnormal range of OCS may pave the way for brain-based strategies to identify children who are more likely to develop OCD and enable the targeting of preventive strategies to reduce risk.

Obsessive-compulsive symptoms and resting-state functional characteristics in pre-adolescent children from the general population

While functional brain characteristics of obsessive-compulsive disorder have been extensively studied, literature on network topology and subnetwork connectivity related to obsessive-compulsive symptoms (OCS) is sparse. Here we investigated the functional brain characteristics of OCS in children from the general population using a multiscale approach. Since we previously observed OCS-related differences in thalamus morphology, we also focused on the network participation of thalamic subregions. The study included 1701 participants (9-12 years) from the population-based Generation R study. OCS were measured using the Short Obsessive-Compulsive Disorder Screener. We studied the brain network at multiple scales: global network topology, subnetwork connectivity and network participation of thalamic nodes (pre-registration: https://osf.io/azr9c ). Modularity, small-worldness and average participation coefficient were calculated on the global scale. We used a data-driven consensus community approach to extract a partition of five subnetworks involving thalamic subregions and calculate the within- and between-subnetwork functional connectivity and topology. Multiple linear regression models were fitted to model the relationship between OCS and functional brain measures. No significant associations were found when using our preregistered definition of probable OCS. However, post-hoc analyses showed that children endorsing at least one OCS (compared with controls) had higher modularity, lower connectivity between frontoparietal, limbic and visual networks as well as altered participation of the lateral prefrontal thalamus node. Our results suggest that network characteristics of OCS in children from the general population are partly symptom-specific and severity-dependent. Thorough assessment of symptom dimensions can deepen our understanding of OCS-related brain networks.