OPEN Foundation

H. Wang

Efficacy of ketamine in the rapid treatment of major depressive disorder: a meta-analysis of randomized, double-blind, placebo-controlled studies

Abstract

Background: An increasing number of studies are reporting that ketamine could be treated as a novel antidepressant for major depressive disorder (MDD). Therefore, we performed this meta-analysis to comprehensively and systematically assess the efficacy of ketamine for treating patients with MDD.

Method: Randomized, double-blind, placebo-controlled studies on ketamine versus placebo for treating MDD were searched up to April 2016 in medical databases (PubMed, CCTR, Web of Science, Embase, CBM-disc, and CNKI). Three treatment time points (24 and 72 h, and day 7) were chosen. Response and remission rates were the main outcomes. The random effects model was used. An intention-to-treat analysis was conducted.

Results: Nine high-quality studies that included 368 patients were selected to compare the efficacy of ketamine to placebo. The therapeutic effects of ketamine at 24 and 72 h, and day 7 were found to be significantly better than placebo. Response and remission rates in the ketamine group at 24 and 72 h, and day 7 were 52.2% and 20.6%; 47.9% and 23.8%; and 39.8% and 26.2%, respectively. No significant heterogeneity existed, and the Egger’s test showed no publication bias.

Conclusion: These results indicated that ketamine could yield a good efficacy in the rapid treatment of MDD. Future large-scale clinical studies are needed to confirm our results and investigate the mid- and long-term efficacy of ketamine in treating MDD.

Han, Y., Chen, J., Zou, D., Zheng, P., Li, Q., Wang, H., … & Xie, P. (2016). Efficacy of ketamine in the rapid treatment of major depressive disorder: a meta-analysis of randomized, double-blind, placebo-controlled studies. Neuropsychiatric Disease and Treatment, 12, 2859. 10.2147%2FNDT.S117146

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Activation of 5-HT2A/2C receptors reduces the excitability of cultured cortical neurons

Abstract

The abundant forebrain serotonergic projections are believed to modulate the activities of cortical neurons. 5-HT2 receptor among multiple subtypes of serotonin receptors contributes to the modulation of excitability, synaptic transmissions and plasticity. In the present study, whole-cell patch-clamp recording was adopted to examine whether activation of 5-HT2A/2C receptors would have any impact on the excitability of cultured cortical neurons. We found that 2,5-Dimethoxy-4-iodoamphetamine (DOI), a selective 5-HT2A/2C receptor agonist, rapidly and reversibly depressed spontaneous action potentials mimicking the effect of serotonin. The decreased excitability was also observed for current-evoked firing. Additionally DOI increased neuronal input resistance. Hyperpolarization-activated cyclic nucleotide-gated cationic channels (HCN) did not account for the inhibition of spontaneous firing. The synaptic contribution was ruled out in that DOI augmented excitation and attenuated inhibition to actually favor an increase in the excitability. Our findings revealed that activation of 5-HT2A/2C receptors reduces neuronal excitability, which would deepen our understanding of serotonergic modulation of cortical activities.
Hu, L., Liu, C., Dang, M., Luo, B., Guo, Y., & Wang, H. (2016). Activation of 5-HT 2A/2C receptors reduces the excitability of cultured cortical neurons. Neuroscience letters632, 124-129. 10.1016/j.neulet.2016.08.052
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