Ketamine treatment for depression: a review

Ketamine and its enantiomer esketamine offer rapid antidepressant effects, often within one day, for treatment-resistant depression, with symptom improvement lasting three to seven days. Esketamine received FDA approval in 2019 as an adjunctive treatment for adults with treatment-resistant depression, administered under medical supervision due to a risk evaluation and mitigation strategy. Side effects such as dissociative symptoms, hypertension, and confusion or agitation are generally tolerable and limited to the time of treatment, though longer-term risks including abuse or dependence remain poorly understood. The drug has also been studied for suicidality, obsessive-compulsive disorder, post-traumatic stress disorder, substance abuse, and social anxiety disorder. Research on ketamine may also deepen understanding of mood disorder mechanisms and guide development of new treatments.

Study at a glance

Abstract

-enantiomer, intranasal esketamine, for the treatment of major depressive disorder (MDD). Initial studies found that a single subanesthetic-dose IV ketamine infusion rapidly (within one day) improved depressive symptoms in individuals with MDD and bipolar depression, with antidepressant effects lasting three to seven days. In 2019, esketamine received FDA approval as an adjunctive treatment for treatment-resistant depression (TRD) in adults. Esketamine was approved under a risk evaluation and mitigation strategy (REMS) that requires administration under medical supervision. Both ketamine and esketamine are currently viable treatment options for TRD that offer the possibility of rapid symptom improvement. The manuscript also reviews ketamine's use in other psychiatric diagnoses-including suicidality, obsessive-compulsive disorder, post-traumatic stress disorder, substance abuse, and social anxiety disorder-and its potential adverse effects. Despite limited data, side effects for antidepressant-dose ketamine-including dissociative symptoms, hypertension, and confusion/agitation-appear to be tolerable and limited to around the time of treatment. Relatively little is known about ketamine's longer-term effects, including increased risks of abuse and/or dependence. Attempts to prolong ketamine's effects with combined therapy or a repeat-dose strategy are also reviewed, as are current guidelines for its clinical use. In addition to presenting a novel and valuable treatment option, studying ketamine also has the potential to transform our understanding of the mechanisms underlying mood disorders and the development of novel therapeutics.