RETRACTED: A preliminary naturalistic study of low-dose ketamine for depression and suicide ideation in the emergency department (Retracted article. See vol. 20, pg. 611, 2017)

We examined the preliminary feasibility, tolerability and efficacy of single-dose, intravenous (i.v.) ketamine in depressed emergency department (ED) patients with suicide ideation (SI). Fourteen depressed ED patients with SI received a single i.v. bolus of ketamine (0.2 mg/kg) over 1-2 min. Patients were monitored for 4 h, then re-contacted daily for 10 d. Treatment response and time to remission were evaluated using the Montgomery-Asberg Depression Rating Scale (MADRS) and Kaplan-Meier survival analysis, respectively. Mean MADRS scores fell significantly from 40.4 (S.E.M. = 1.8) at baseline to 11.5 (S.E.M. = 2.2) at 240 min. Median time to MADRS score <= 10 was 80 min (interquartile range 0.67-24 h). SI scores (MADRS item 10) decreased significantly from 3.9 (S.E.M. = 0.4) at baseline to 0.6 (S.E.M. = 0.2) after 40 min post-administration; SI improvements were sustained over 10 d. These data provide preliminary, open-label support for the feasibility and efficacy of ketamine as a rapid-onset antidepressant in the ED.