Progress, potential and pitfalls of ketamine as a treatment for depression

Evidence supporting the use of intravenous ketamine and intranasal esketamine for depression has dramatically increased with a large number of clinical trials and real-world effectiveness studies supporting antidepressant effects. Larger studies have provided reassuring data supporting an adequate safety profile, including safety data with long-term treatment. Alternative routes of administration have shown promise for improving scalability; however, efficacy as compared to intravenous ketamine remains unclear. Promising preliminary data support ketamine's efficacy in other conditions, such as bipolar disorders, personality disorders, posttraumatic stress, and obsessive-compulsive disorder. Further research is needed to optimize protocols, such as combining ketamine with other interventions. Functional unblinding, expectancy-related bias, and treatment costs remain challenges for the field.