Increased error-related brain activity in youth with obsessive-compulsive disorder and unaffected siblings.

BACKGROUND: The pathophysiology of obsessive-compulsive disorder (OCD) involves increased activity in cortico-striatal circuits connecting the anterior cingulate cortex (ACC) with other brain regions. The error-related negativity (ERN) is a negative deflection in the event-related potential following an erroneous response and is thought to reflect ACC activity. This study was done to assess the ERN as a biomarker for OCD by comparing ERN amplitudes in pediatric OCD patients, unaffected siblings of pediatric OCD patients, and healthy controls.
METHODS: The ERN and correct response negativity (CRN) were measured during an Eriksen flanker task to assess performance monitoring in 40 youth with a lifetime diagnosis of OCD, 19 unaffected siblings of OCD patients, and 40 unrelated healthy comparison subjects ranging in age from 10 to 17 years. ERN and CRN amplitudes were compared between groups using linear regression by the generalized estimating equation method to account for correlated data.
RESULTS: Compared to healthy controls, ERN amplitude was significantly increased in both pediatric OCD patients and unaffected siblings. There were no significant group differences in CRN amplitude. ERN amplitude in patients was unrelated to OCD symptom severity, current diagnostic status, or treatment effects.
CONCLUSIONS: Increased error-related brain potentials were observed not only in pediatric OCD patients but also in unaffected siblings. The results provide evidence that enhanced error-related brain activity may serve as a biomarker for OCD in youth that is independent of the presence of clinical symptoms. The ERN may be a useful quantitative phenotype in genetic studies of OCD.