WHAT IS KNOWN AND OBJECTIVE: Ketamine in a subanaesthetic dose has been shown to produce rapid antidepressant effects. Here, we describe a long-term follow-up case of a Korean patient with severe major depression who received repeated ketamine intravenous therapy (KIT). CASE DESCRIPTION: A 49-year-old woman with a 6-year history of treatment-resistant major depression was given KIT once every 1...