Error-Related Brain Potentials as Biomarkers of Pathology Severity and Treatment Resistance in Patients With Obsessive-Compulsive Disorder.

Obsessive-compulsive disorder (OCD) is a psychiatric condition that varies considerably in severity and resistance to treatment. The aim of this study was to identify error detection abnormalities in OCD patients using evoked potential recordings and to determine whether links could be established between individual patients' error detection processes and their severity and resistance to treatment. To answer this question, the potentials evoked by participants' responses to a flanker task, i.e., the error-related negativity (ERN/CRN component) and subsequent positivity (Pe/Pc component), were recorded. Twenty-six OCD patients with a wide range of pathology severity and treatment resistance and 26 control participants matched for gender, age, and education level with the patients were included in the study. The amplitude of the error-related negativity (ERN) evoked by false responses was positively correlated with the severity of patients' pathology, while the lower the amplitude of the negativity evoked by correct responses (CRN), the more resistant patients were to treatment. The ERN/CRN components could therefore be used as markers of the severity and treatment resistance of OCD patients' pathology. Furthermore, under the present experimental conditions, the positive Pe/Pc component, supposed to reflect patients' awareness of the correctness of their responses, was virtually absent compared to control participants. This suggests a major deficit in the patients' monitoring of the consequences of their actions. The discovery of this disappearance of action feedback signals in patients leads to proposing an original neurodevelopmental model for the onset of pathology in childhood or adolescence.