Subanesthetic ketamine alters EEG signal complexity: Implications for treatment stratification in depression.
Journal of affective disorders October 1, 2025 Weng-Lam Chan, Sebastian Olbrich, Xinwen Jiang et al. 3 citations
Ketamine, a drug that blocks NMDA receptors and is thought to boost neuroplasticity, increased whole-brain EEG signal complexity during infusion in patients with major depressive disorder (MDD), most of whom had treatment-resistant depression. Higher complexity at the end of infusion predicted less symptom improvement the next day, while lower occipital complexity before treatment predicted a favorable response. A logistic model using occipital complexity had moderate predictive accuracy. No changes were seen in a different complexity measure, suggesting it is not useful as a biomarker. Occipital EEG complexity may help predict which patients will benefit from ketamine therapy.