Cortical thickness of the posterior cingulate cortex is associated with the ketamine-induced altered sense of self: An ultra-high field MRI study.
Lena Vera Danyeli, Zümrüt Duygu Sen, Lejla Colic, Nils Opel, Alexander Refisch, Nikolai Blekic, Tamar Macharadze, Moritz Kretzschmar, Matthiash J Munk, Christian Gaser, Oliver Speck, Martin Walter, Meng Li
Journal of Psychiatric Research April 1, 2024 DOI: 10.1016/j.jpsychires.2024.02.019 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized, placebo-controlled, double-blind cross-over magnetic resonance imaging study Peer reviewed |
|---|---|
| Sample size | 35 |
| Population | Healthy male participants (mean age 25.1 ± 4.2 years) |
| Intervention | Ketamine |
| Dose | subanesthetic doses |
| Topics | Esketamine Ketamine |
| Citations | 3 |
| Key points | PCC cortical thickness negatively correlated with disembodiment scores (R = -0.54, p < 0.001), while pgACC thickness showed no significant association with ketamine-induced altered sense of self. |
Abstract
Subanesthetic doses of ketamine induce an antidepressant effect within hours in individuals with treatment-resistant depression while it furthermore induces immediate but transient psychotomimetic effects. Among these psychotomimetic effects, an altered sense of self has specifically been associated with the antidepressant response to ketamine as well as psychedelics. However, there is plenty of variation in the extent of the drug-induced altered sense of self experience that might be explained by differences in basal morphological characteristics, such as cortical thickness. Regions that have been previously associated with a psychedelics-induced sense of self and with ketamine's mechanism of action, are the posterior cingulate cortex (PCC) and the pregenual anterior cingulate cortex (pgACC). In this randomized, placebo-controlled, double-blind cross-over magnetic resonance imaging study, thirty-five healthy male participants (mean age ± standard deviation (SD) = 25.1 ± 4.2 years) were scanned at 7 T. We investigated whether the cortical thickness of two DMN regions, the PCC and the pgACC, are associated with disembodiment and experience of unity scores, which were used to index the ketamine-induced altered sense of self. We observed a negative correlation between the PCC cortical thickness and the disembodiment scores (R = -0.54, p < 0.001). In contrast, no significant association was found between the pgACC cortical thickness and the ketamine-induced altered sense of self. In the context of the existing literature, our findings highlight the importance of the PCC as a structure involved in the mechanism of ketamine-induced altered sense of self that seems to be shared with different antidepressant agents with psychotomimetic effects operating on different classes of transmitter systems.
Comparable studies
Other randomized controlled trials on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Subanesthetic Effects of the Noncompetitive NMDA Antagonist, Ketamine, in Humans Healthy human subjects recruited from the community | 1994 | Randomized controlled trial | n = 19 |
| Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial Patients with treatment-resistant major depression experiencing a major depressive episode | 2013 | Randomized controlled trial | n = 73 |
| Remifentanil-induced Postoperative Hyperalgesia and Its Prevention with Small-dose Ketamine Patients undergoing major abdominal surgery | 2005 | Randomized controlled trial | n = 75 |
| Efficacy of Intravenous Ketamine for Treatment of Chronic Posttraumatic Stress Disorder Patients with chronic PTSD related to a range of trauma exposures | 2014 | Randomized controlled trial | n = 41 |
| Ketamine-Induced Deficits in Auditory and Visual Context-Dependent Processing in Healthy Volunteers Healthy volunteers | 2000 | Single-blind placebo-controlled study | n = 20 |
Citations in the library
Cited by 3
- Esketamine in depression: putative biomarkers from clinical research. European Archives of Psychiatry and Clinical Neuroscience July 13, 2024
- Can ketamine and other glutamate receptor modulators be considered entactogens? Psychiatry Research July 1, 2025
- Association between S-ketamine induced changes in glutamate levels in the pregenual anterior cingulate cortex and plasma brain-derived neurotrophic factor in healthy subjects. Frontiers in Psychiatry 2025
Cites 44
- A Randomized Trial of an N-methyl-D-aspartate Antagonist in Treatment-Resistant Major Depression Archives of General Psychiatry August 1, 2006
- Subanesthetic Effects of the Noncompetitive NMDA Antagonist, Ketamine, in Humans Archives of General Psychiatry March 1, 1994
- Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin Proceedings of the National Academy of Sciences January 23, 2012
- Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proceedings of the National Academy of Sciences April 11, 2016
- Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression Frontiers in Pharmacology January 17, 2018
and 39 more in the library