Previous studies have demonstrated ketamine to have a rapid antidepressant effect in some patients with treatment-resistant depression (TRD), but the effect is unfortunately not sustained in the long term. In this study, we report on the clinical use of ongoing maintenance ketamine infusions in a group of patients with TRD, beyond an acute course of 6 to 8 ketamine infusions.. MPFT staff can use the OVID link, or you can request a copy of this article by replying to this email. Please ensure you are clear which article you are requesting.