Only a few studies have looked at the efficacy of Ketamine for treating treatment-resistant depression (TRD) in large clinical populations.

A retrospective record review analysis with more than 400 TRD participants showed that Ketamine is a quick and secure treatment in a real-world patient population.

424 patients with major depressive disorder or another mood illness who had at least one Ketamine infusion at a specialized clinic were included in the study. Six Ketamine infusions totaling 0.5 mg/kg/40 minutes were given over the course of 21 days. Depending on the clinical outcome, maintenance infusions were provided. All participants completed the Generalized Anxiety Disorder-7 and the Patient Health Questionnaire-9 (PHQ-9) at each clinic visit (GAD-7).

Over time, the primary outcomes showed significant improvements from the baseline. Within 6 weeks of the start of the infusion, a 50% response rate and a 20% remission rate for depressed symptoms were noted based on PHQ-9 self-report data. After 10 infusions, the response and remission rates were 72% and 38%, respectively, and the self-harm/suicidal ideation (SI) symptom ratings decreased by 50% after 6 weeks. After six treatments, half of the individuals with SI at baseline no longer had it. On the GAD-7, there was a 30% decrease in anxiety symptoms.

The study thus concluded that Ketamine effectively reduced symptoms of SI, depression, and anxiety. (Medscape - Sep 14, 2022.)