A Double-Blinded, Randomized, Placebo-Controlled Sub-Dissociative Dose Ketamine Pilot Study in the Treatment of Acute Depression and Suicidality in a Military Emergency Department Setting

The study was a double-blinded, randomised, placebo-controlled proof-of-concept trial conducted in an emergency department (ED) setting with an active duty convenience sample. Eligible participants were service members presenting to the ED with depression and suicidal thinking who met criteria for inpatient psychiatric admission. Subjects were randomised to receive either a sub-dissociative intravenous dose of ketamine (0.2 mg/kg) or an equivalent volume of normal saline (placebo). The trial relied on volunteer staff across two departments and was unfunded. Participants were assessed during a 4-hour ED observation period, again at hospital discharge, and at a 2-week post-discharge follow-up. The principal symptom measures analysed were BSS and BHS scores (reported in the text as measures of suicidality and hopelessness). Changes in these scores over the 4-hour ED observation were analysed using repeated measures analysis of variance. Scores at hospital discharge, at 2-week follow-up, and length of hospital stay (in days) were compared between groups using Student t tests. The extracted text reports substantial methodological problems that limited analyzable data, and the analyzable sample ended up being small (see Results).

Methodological difficulties restricted analyzable data to ten subjects in total. Of these, three received ketamine and seven received placebo. During the 4-hour ED observation period two of the three subjects who received ketamine experienced dramatic decreases in suicidality and hopelessness within 40 minutes of administration. No comparable acute improvements were observed among any of the seven placebo recipients over the 4-hour ED course. The authors report a statistical improvement in the intervention group versus controls for the acute (ED) measures, although the extracted text does not provide p-values, confidence intervals or detailed effect sizes. At hospital discharge there was no clinically significant difference between the ketamine and placebo groups, and by the 2-week follow-up the ketamine recipients “did as well as” those receiving placebo, according to the authors. The authors state they did not observe rebound increases in suicidality among ketamine-treated subjects. No subjects described adverse symptoms in the available data. The Results section of the extract specifies that repeated measures ANOVA was used for the 4-hour comparisons of BSS and BHS, and Student t tests were used for discharge and 2-week comparisons and for length of stay, but detailed numerical results beyond the counts and the qualitative descriptions above are not included in the extracted text.

The authors interpret the remaining data from the truncated trial as suggesting potential for intravenous ketamine as a rapid-acting intervention to reduce acute suicidal ideation and hopelessness in active duty service members. They highlight the particularly rapid onset seen in some individuals (improvement within 40 minutes) and note that, in this small sample, the acute benefits persisted for a number of days before equalising with placebo. They situate these observations as consistent with other published studies of ketamine’s rapid antidepressant and anti-suicidal effects and suggest possible future applications in emergency or field settings to reduce the need for hospitalisation or medical evacuation. The authors also caution that ketamine is not an ideal long-term treatment because of its abuse potential and point to ongoing research into other NMDA receptor antagonists, including agents targeting receptor subunits, which might retain effectiveness without dissociative side effects. Key limitations acknowledged by the authors are central to their interpretation: the trial was terminated early because of record-keeping difficulties; it was unfunded and relied on volunteer personnel across departments; and these operational problems limited sample size and data completeness. The authors report plans to restart the study with a funded, centralised research nurse to improve drug administration and outcome tracking. They conclude that further research is needed to confirm and extend these preliminary findings.

The authors state that the intended larger trial was terminated early due to record-keeping and operational difficulties in an unfunded, volunteer-driven study. Despite the trial’s failure to complete as planned, analysis of the remaining ten subjects suggested that 67% (two of three) of ketamine recipients showed significant acute improvement in hopelessness and suicidality in the ED, whereas placebo recipients remained unchanged during the same observation period. No rebound suicidality was observed, and ketamine recipients performed comparably to controls over the course of hospitalisation and at follow-up. The authors conclude that IV ketamine may be an effective acute intervention for depression and suicidality in the active duty military population, that effects can persist for days before equalising with placebo, and that further research—including investigation of other NMDA antagonists and a restarted trial with funded personnel—is warranted.