Repeated ketamine injections in synergy with antidepressants for treating refractory depression: A case showing 6-month improvement

Introduction

Major depressive disorder imposes a large global burden and a substantial minority of patients—commonly estimated at around 30%—meet criteria for treatment‑resistant depression (TRD). Earlier research has shown that ketamine produces rapid antidepressant effects across multiple routes of administration, but optimal dosing remains uncertain: some studies report greater benefit with doses above the frequently used 0.5 mg/kg intravenous bolus, while others find 0.5 mg/kg numerically superior to higher doses. Long‑term intravenous regimens have been proposed to extend the brief response after single doses, but chronic ketamine use raises safety concerns such as addiction and cognitive impairment. Wang and colleagues present a single‑patient case report intended to illustrate the clinical course, tolerability and durability of effect following repeated, rapidly administered, high‑dose intravenous ketamine given alongside ongoing antidepressant therapy. The report addresses the open question of whether escalation above 0.5 mg/kg and repeated rapid injections can be both tolerated and associated with sustained improvement in a person with longstanding, refractory major depression.