Esketamine Adjuvant Therapy for Patients With Chronic Visceral Pain Comorbid Major Depressive Disorder

Randomized, parallel-group study in patients with chronic visceral pain comorbid major depressive disorder comparing three IV esketamine dose groups (0.125, 0.25, 0.50 mg/kg; 2×/week) plus duloxetine versus an active comparator (pregabalin 75 mg tid plus duloxetine).

Primary aim is to evaluate efficacy and safety (analgesic and antidepressant effects) of adjunctive esketamine; treatment lasts 2 weeks with a 2‑week observation follow-up.