Preliminary evidence that serum interleukin-6 is a candidate biomarker of response to esketamine in treatment-resistant depression.
Journal of psychopharmacology (Oxford, England) April 24, 2026 Marco Colizzi, Elisa Morandin, Veronica Croccia et al.
In adults with treatment-resistant depression, higher baseline levels of the inflammatory marker interleukin-6 (IL-6) were associated with more rapid symptom reduction after intranasal esketamine treatment, while lower IL-6 predicted greater symptom severity and higher disability. IL-6 levels themselves did not change over the 24-week open-label phase 2 trial. The finding suggests that inflammation may play a role in treatment resistance and that baseline IL-6 could help guide personalized treatment decisions.