Ketamine and other N-methyl-D-aspartate receptor antagonists in the treatment of depression: a perspective review
Ballard, E. D., Ladarola, N. D., Lundin, N. B., Machado-Vieira, R., Niciu, M. J., Nugent, A. C., Richards, E. M., Vande Voort, J. L., Zarate, C. A.
This review (2014) examines ketamine as a prospective treatment option for patients with depression and provides an overview of its role within the glutamate system, its antidepressant mechanisms of action, safety profile, and evidence from clinical studies that investigated the efficacy of single or multiple infusions. Furthermore, it compares alternative modes of ketamine administration and highlights fundamental research on other types of NMDA agonists that may have less psychotomimetic effects.
Abstract
Current pharmacotherapies for major depressive disorder (MDD) and bipolar depression (BDep) have a distinct lag of onset that can generate great distress and impairment in patients. Furthermore, as demonstrated by several real-world effectiveness trials, their efficacy is limited. All approved antidepressant medications for MDD primarily act through monoaminergic mechanisms, agonists or antagonists with varying affinities for serotonin, norepinephrine and dopamine. The glutamate system has received much attention in recent years as an avenue for developing novel therapeutics. A single subanesthetic dose infusion of the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has been shown to have rapid and potent antidepressant effects in treatment-resistant MDD and BDep. In a reverse translational framework, ketamine’s clinical efficacy has inspired many preclinical studies to explore glutamatergic mechanisms of antidepressant action. These studies have revealed enhanced synaptic plasticity/synaptogenesis via numerous molecular and cellular mechanisms: release of local translational inhibition of brain-derived neurotrophic factor and secretion from dendritic spines, mammalian target of rapamycin activation and glycogen synthase kinase-3 inhibition. Current efforts are focused on extending ketamine’s antidepressant efficacy, uncovering the neurobiological mechanisms responsible for ketamine’s antidepressant activity in biologically enriched subgroups, and identifying treatment response biomarkers to personalize antidepressant selection. Other NMDA receptor antagonists have been studied both preclinically and clinically, which have revealed relatively modest antidepressant effects compared with ketamine but potentially other favorable characteristics, for example, decreased dissociative or psychotomimetic effects; therefore, there is great interest in developing novel glutamatergic antidepressants with greater target specificity and/or decreased adverse effects.