Mechanisms of Ketamine and its Metabolites as Antidepressants
Biochemical Pharmacology December 1, 2021 E. Hess, L. Riggs, M. Michaelides et al. 167 citations
Ketamine, an anesthetic, produces rapid antidepressant effects in people with treatment-resistant depression when given at sub-anesthetic doses, leading to FDA approval of esketamine. The mechanisms behind these effects remain under investigation, with evidence suggesting that ketamine's metabolites, such as (2R,6R)-hydroxynorketamine (HNK), may play a key role. HNK shows antidepressant potential in preclinical tests without ketamine's dissociative or abuse-related side effects. The review discusses how ketamine and its metabolites influence glutamate signaling through NMDARs and AMPARs, synaptic changes via BDNF, opioid receptor interactions, and enhancement of serotonin, norepinephrine, and dopamine signaling. Targeting these pathways could yield new rapid-acting antidepressants with fewer side effects.