MAYBE, but it's too soon to tell. There is limited evidence that ketamine by itself is effective in the very short term. Single-dose intravenous (IV) ketamine is more likely than placebo (odds ratio = 11-13) to produce improvement (> 50%) in standardized depression scores in 1 to 3 days, lasting up to a week. Twice- or thriceweekly IV ketamine improves symptom scores by 20%-25% over 2 weeks...