Neural correlates of symptom dimensions in pediatric obsessive-compulsive disorder: a functional magnetic resonance imaging study.

OBJECTIVE: Neuroimaging studies have identified distinct neural correlates of obsessive-compulsive disorder (OCD) symptom dimensions in adult subjects and may be related to functional abnormalities in different cortico-striatal-thalamic neural systems underlying cognition and affective processing. Similar symptom dimensions are apparent in childhood and adolescence, but their functional neural correlates remain to be elucidated.

METHOD: Pediatric subjects with OCD (n = 18) and matched controls (n = 18), ages 10 to 17 years, were recruited for two functional magnetic resonance imaging experiments. They were scanned while viewing alternating blocks of symptom provocation (contamination-related or symmetry-related) and neutral pictures and imagining scenarios related to the content of each picture type.

RESULTS: The subjects with OCD demonstrated reduced activity in the right insula, putamen, thalamus, dorsolateral prefrontal cortex, and left orbitofrontal cortex (contamination experiment) and in the right thalamus and right insula (symmetry experiment). Higher scores on OCD symptom-related measures (contamination and total severity) were significantly predictive of reduced neural activity in the right dorsolateral prefrontal cortex during the contamination experiment.

CONCLUSIONS: Our findings indicate reduced activity in neural regions underlying emotional processing, cognitive processing, and motor performance in pediatric subjects with OCD compared with the controls. These between-group differences are present during both contamination and symmetry provocation experiments and during symptom provocation as well as viewing neutral pictures. The direction of activity is in contrast to adult findings in the insula and in components of cortico-striatal-thalamic neural systems. Our findings suggest developmental effects on neural systems underlying symptom dimensions in pediatric OCD.