Acute and long-term effects of repeated ketamine infusions in treatment-resistant depression and associated metabolite changes.
Psychiatry and clinical neurosciences July 15, 2025 Hitoshi Sakurai, Daiki Setoyama, Takahiro A Kato et al. 1 citation
In an open-label study of 30 patients with treatment-resistant depression, four intravenous ketamine infusions (0.5 mg/kg) over two weeks rapidly reduced depression severity: the average Montgomery-Åsberg Depression Rating Scale score fell from 30.6 to 20.3 after the fourth infusion, and 26.7% of participants achieved remission. However, only 13.3% remained in remission at 12 months. Early changes in the metabolite 3-hydroxybutyrate predicted the degree of improvement both after the fourth infusion and at 12 months, suggesting it could serve as a biomarker for treatment response. The findings point toward more individualized use of ketamine infusions.