Symptom trajectories and clinical outcomes of intravenous ketamine in treatment-resistant depression: A real-world study using group-based trajectory modeling.
Journal of affective disorders January 23, 2026 Reinhard Janssen-Aguilar, Jithin Joseph, Huda Al-Shamali et al.
In a retrospective chart review of 209 adults with treatment-resistant depression treated with intravenous ketamine, depressive and anxiety symptoms improved significantly over four or six infusions, but the improvements were modest and highly variable across individuals. Anxiety symptoms improved more slowly and less robustly than depressive symptoms. End-of-treatment response and remission rates were numerically higher after six infusions than after four, but the difference was not statistically significant. Four distinct patterns of symptom change emerged for both depression and anxiety, highlighting the heterogeneity of treatment response. Durability after six infusions could not be assessed because follow-up data were available only for the four-infusion group.