A decade has now passed since research into the antidepressant effects of ketamine began in earnest, after the clinical trial reported by Zarate et al. in 2006 (1). In that proof-of-concept study, 18 medication-free patients with treatment-resistant major depressive disorder (TRD) showed a large reduction in core depressive symptoms within hours of receiving a single low-dose 0.5 mg/kg intravenous infusion of ketamine as measured by the 21-item Hamilton Depression Rating Scale compared with saline placebo.
Murrough, J. W. (2016). Ketamine for Depression: An Update. Biological Psychiatry, 80(6), 416-418. http://dx.doi.org/10.1016/j.biopsych.2016.07.005
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