The Role of Glutamate Underlying Treatment-resistant Depression
Jeongseop Kim, Tae-Eun Kim, Seung Hwan Lee, Ja Wook Koo
Clinical Psychopharmacology and Neuroscience July 10, 2023 DOI: 10.9758/cpn.22.1034 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Intervention | Ketamine |
| Topics | Depression |
| Citations | 29 |
| Key findings | Argues that the glutamate hypothesis, alongside monoamine modulation, helps explain treatment-resistant depression and ketamine's antidepressant effects, which the authors attribute to mechanisms such as NMDAR inhibition and disinhibition in GABAergic interneurons. The review also discusses preclinical animal models and sex differences in ketamine response. |
Abstract
The monoamine hypothesis has significantly improved our understanding of mood disorders and their treatment by linking monoaminergic abnormalities to the pathophysiology of mood disorders. Even 50 years after the monoamine hypothesis was established, some patients do not respond to treatments for depression, including selective serotonin reuptake drugs. Accumulating evidence shows that patients with treatment-resistant depression (TRD) have severe abnormalities in the neuroplasticity and neurotrophic factor pathways, indicating that different treatment approaches may be necessary. Therefore, the glutamate hypothesis is gaining attention as a novel hypothesis that can overcome monoamine restrictions. Glutamate has been linked to structural and maladaptive morphological alterations in several brain areas associated with mood disorders. Recently, ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, has shown efficacy in TRD treatment and has received the U.S. Food and Drug Administration approval, revitalizing psychiatry research. However, the mechanism by which ketamine improves TRD remains unclear. In this review, we re-examined the glutamate hypothesis, bringing the glutamate system onboard to join the modulation of the monoamine systems, emphasizing the most prominent ketamine antidepressant mechanisms, such as NMDAR inhibition and NMDAR disinhibition in GABAergic interneurons. Furthermore, we discuss the animal models used in preclinical studies and the sex differences in the effects of ketamine.
Comparable studies
Other narrative reviews on depression, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Synaptic Dysfunction in Depression: Potential Therapeutic Targets | 2012 | Review | |
| Mindfulness-Based Cognitive Therapy for Depression: A New Approach to Preventing Relapse | 2003 | Review | |
| Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation Adults with treatment-resistant depression | 2021 | Review | |
| Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function. General population | 2019 | Integrative review | |
| Sudarshan Kriya Yogic Breathing in the Treatment of Stress, Anxiety, and Depression: Part II—Clinical Applications and Guidelines | 2005 | Review |