Ketamine: A Review for Clinicians.

A growing series of clinical trials and case series now suggest that ketamine-originally used as an anesthetic agent-potentially offers an exciting new treatment option for severe depression. Increasing numbers of studies show that ketamine can provide prompt relief for many depressed patients, including those with severe treatment-refractory depression. Although the effects of a single treatment are commonly short-lived, multiple infusion protocols may offer sustained relief. The uniquely rapid onset of antidepressant action raises the potential for ketamine use in a variety of clinical situations, including the prevention or shortening of hospital stays, the treatment of acute suicidal ideation, and the facilitation of medication crossovers. Ketamine, in combination with other multimodal treatment approaches, including psychotherapy, may further augment response effect and duration. Promises of efficacy have led to increasingly unbridled use to treat a variety of psychiatric disorders, with diverse approaches and treatment environments, despite inadequate data demonstrating the true clinical efficacy and safety of the various protocols or a thorough understanding of mechanisms of action. This article briefly reviews the history of ketamine's development as a potential antidepressant, current hypotheses related to its mechanisms of action, and existing evidence for its safety and efficacy with a focus on clinicians' interests.