Acute subanesthetic ketamine-induced effects on the mismatch negativity and their relationship to early and sustained treatment response in major depressive disorder.
Journal of psychopharmacology (Oxford, England) February 26, 2025 Sara de la Salle, Jennifer L Phillips, Pierre Blier et al. 3 citations
A sub-anesthetic dose of ketamine, an NMDAR antagonist, produces rapid antidepressant effects in treatment-resistant major depressive disorder. In 24 patients, ketamine reduced frontal mismatch negativity (MMN) amplitude, theta event-related oscillations, and source-localized frontal generator activity immediately and 2 hours after infusion, compared to midazolam. Larger reductions in MMN measures, particularly left frontal amplitude and theta oscillations, correlated with and predicted greater early and sustained symptom improvement on the Montgomery-Åsberg Depression Rating Scale. Baseline phase-locking factor also predicted sustained response. The findings suggest that acute NMDAR blockade reduces frontal MMN, and that MMN indices may serve as non-invasive biomarkers for predicting antidepressant response to glutamatergic agents.