Effectiveness of Ketamine in Treatment-Resistant Depression: A Systematic Review and Meta-Analysis

Abstract

In relation to depression and its treatment, there are numerous medications that help in the treatment, whose mechanism of action is inhibiting selective serotonin reuptake or increasing the bioavailability of neurotransmitters in the central nervous system. However, a drug in the hypnotic class, ketamine increases the release of brainderived neurotrophic factor, a protein that helps neurons develop synapses. Ketamine also affects glutamate transmission by blocking NMDA receptors. This makes ketamine have antidepressant effects in patients with treatment-resistant depression. It also increases the speed at which these patients respond to antidepressant medications. One study administered ketamine intravenously at subanesthetic doses found that it could rapidly reduce symptoms of treatment-resistant depression in patients. This is a systematic review study that was designed based on the criteria established in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guide, considering the flow diagram and the PRISMA checklist. Ninety of the respondents who received the ketamine and oral antidepressant intervention showed an improvement. This review confirms that ketamine is beneficial in the treatment of patients with depressive disorder and generalized anxiety disorder. However, ketamine showed excellent results associated with antidepressants compared to other drugs, for example midazolam did not reduce 50% of the Montgomery-Asberg depression scale score.