Temporal Immune Effects of Oral Ketamine on PTSD: Transcriptomic Evidence of Short-Term Inflammation Suppression and Long-Term Immune Remodelling
medRxiv Preprint Server May 26, 2025 Nathan J. Wellington, Bonnie L. Quigley, Ana P. Bouças et al. preprint
A six-week course of oral ketamine produced substantial and persistent changes in gene expression in 23 people with PTSD. Short-term effects included suppression of inflammation and antimicrobial activity; long-term effects shifted toward sustained immune regulation, inflammation remodulation, and tissue repair. Over four weeks, the number of genes whose activity changed rose by 37%, the magnitude of expression changes increased 6.5-fold, and pathway activity strengthened 8.8-fold. Key immune and inflammatory pathways modulated included interferon alpha/beta signaling, IL-17 signaling, cytokine storm signaling, neutrophil degranulation, and antimicrobial peptide signaling. Central regulators such as IL-6, IL-1β, IFI27, IL-10, CXCL8, SOCS1/3, and CAMP were implicated. These molecular changes point to mechanisms underlying ketamine's long-term therapeutic effects and suggest avenues for personalized maintenance therapy to prevent relapse.