Event-related potentials in drug-naïve pediatric patients with obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) is one of the most common mental health disorders, characterized by obsessive thoughts and/or compulsive behaviors, which may involve specific disorders in cognition and/or information processing. Event-related potentials (ERPs) are commonly used as physiological measures of cognitive function as they are easily measured and noninvasive. In the present study, 20 drug-naïve pediatric patients with OCD were compared with 20 healthy control participants who were age- and sex-matched to perform the ERP. Based on the guidelines for evoked potential measurement, the P300 and mismatch negativity (MMN) were obtained by auditory odd-ball tasks. We found that the amplitudes of the P300 components in the Fz, Cz, Pz, C3, and C4 regions were significantly smaller in the OCD group compared with the control group. There were no between-group differences in P300 latency, MMN amplitude, or MMN latency. Moreover, we found significant correlations between scores on the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) and P300 amplitudes at Cz, Pz, and C3. The present study is the first to report smaller P300s and the associations between P300 abnormalities and CY-BOCS scores.