Journal of Psychiatric Research
December 24, 2014
Ke Xu, J. Krystal, Y. Ning et al.
65 citations
Ketamine, a drug that blocks NMDA glutamate receptors, produces symptoms resembling schizophrenia. Analyzing the Positive and Negative Syndrome Scale (PANSS) in four groups—135 healthy people given ketamine or saline, 187 chronic ketamine abusers, 154 early-course schizophrenia patients, and 522 chronic schizophrenia patients—revealed five similar symptom dimensions (positive, negative, cognitive, depressed, excitement/dissociation) across all groups. The chronic ketamine group's symptom structure more closely matched the schizophrenia groups than the acute ketamine group did. Symptoms were milder in ketamine users than in schizophrenia patients (Cohen's d = 0.7). The findings suggest ketamine-induced psychosis shares symptom dimensions with schizophrenia, though confounding factors warrant caution.
Journal of Neuroinflammation
September 15, 2021
Yanling Zhou, Chengyu Wang, Xiaofeng Lan et al.
61 citations
Patients with treatment-resistant depression (TRD) who also experience pain show a higher antidepressant response rate and remission rate after six infusions of ketamine compared to those without pain. Before treatment, levels of inflammatory cytokines GM-CSF and IL-6 were elevated in the pain group. After ketamine, many inflammatory cytokines decreased in the pain group, while only TNF-α decreased in the non-pain group. Changes in IL-6 were linked to improvements in both pain intensity and depressive symptoms. The findings suggest that elevated inflammation contributes to individual differences in TRD patients with and without pain, and ketamine's antidepressant and analgesic effects may involve modulating inflammation.
Journal of Affective Disorders
May 1, 2019
Wei Zheng, Xiaohong Li, Xiao-Min Zhu et al.
57 citations
An updated meta-analysis of 17 randomized controlled trials involving 1,035 people with major depressive disorder found that adding ketamine alone to electroconvulsive therapy does not improve depressive symptoms compared with other anesthetic agents at any time point. Combining ketamine with other anesthetics showed a short-term advantage in reducing depressive symptoms early in treatment, but this benefit did not persist after the full course of ECT or at the end of the study. Most subgroup analyses confirmed the lack of significant effect. Ketamine alone increased blood pressure more than other anesthetics. Results for neurocognitive function were mixed.