Exploring Potential Neural Correlates of Treatment Response in Patients with Obsessive–Compulsive Disorder

Abstract: While precision medicine approaches are still an emerging field in psychiatric research, there is already significant interest in exploring biological markers that forecast treatment responses, as well as support in the development of targeted interventions. This explorative pilot study investigated the role of event-related potentials (ERPs) – specifically the error negativity/error-related negativity (Ne/ERN), correct-response negativity (CRN), neural indicators of conflict monitoring (N2), and attention allocation (P3) – in predicting treatment response for patients with obsessive–compulsive disorder (OCD) undergoing evidence-based psychopharmacological and cognitive-behavioral treatment within a naturalistic, intensive inpatient setting. We included 23 OCD patients and examined the correlations between baseline ERPs, elicited by a flanker task, and symptom severity, as well as the potential of these neural indices to predict treatment response. Results indicated that baseline obsessive–compulsive symptom severity was not only associated with a larger Ne/ERN but also with faster response times on correct trials. Regarding the prediction of treatment outcomes, neither neural nor behavioral variables significantly predicted changes in obsessive–compulsive symptoms, depressive symptoms, or global functioning. However, some associations approached significance and were discussed with caution. Overall, this study may provide a preliminary foundation for the potential application of neurobiological measures in precision medicine approaches within psychiatry. Future research should build upon these findings by conducting randomized controlled trials (RCT) that more clearly account for confounding variables, as well as larger naturalistic studies to enhance ecological validity. Such efforts will help improve the reliability and practical applicability of these insights.