Ketamine in depression and electroconvulsive therapy
Current Opinion in Anaesthesiology – October 01, 2021
Source: CrossRef
Summary
A single intravenous dose of 0.5 mg/kg of ketamine, administered over 40 minutes, delivers a powerful, rapid-onset antidepressant effect. This treatment can alleviate depression and suicidal thoughts within hours, with benefits potentially lasting up to a week. Ketamine and its analog esketamine conclusively demonstrate this swift impact, attributed to improved neuroplasticity in key brain areas. Repeated nasal spray esketamine may prevent depression relapse. Ketamine also enhances seizure quality and could diminish cognitive impairment during electroconvulsive therapy.
Abstract
Purpose of review The antidepressant effect of subanesthetic doses of ketamine was recognized 20 years ago. This review briefly summarizes the current understanding of the antidepressant mechanisms and the available clinical research on the use of racemic ketamine and enantiomer esketamine for depression. Recent findings The antidepressant effect of subanesthetic doses of ketamine is currently considered to be predominantly mediated by improved neuroplasticity in cortico-limbic areas in the brain. Single dose of 0.5 mg/kg of ketamine infused intravenously over 40 min, or single intranasal dose of esketamine cause rapid antidepressant and antisuicidal effects within hours of administration, and the antidepressant effect may last up to a week. Repeated administration of nasal spray esketamine is considered to prevent relapse of depression. Longitudinal studies are currently insufficient. When used in various doses for anesthetic induction for electroconvulsive therapy, ketamine improves seizure quality and may possibly diminish posttherapy cognitive impairment. Summary A rapid onset antidepressive effect of ketamine and esketamine has been proven conclusively. The results of extensive basic science research of the mechanism of action of low-dose ketamine doses has led to an alternative hypothesis of the pathophysiology of depression and the development of a novel neurotrophic concept of depression. Further longitudinal studies are warranted to determine the safety and efficacy of repeated administration of ketamine and its analogs to prevent relapse and recurrence of depression.