IV Ketamine for Suicidal TRD: Real-World Case Series Insights (Bangladesh, 2024)

Case Series Reveals Variable IV Ketamine Response in Suicidal TRD

A 2024 case series published in the Bangladesh Journal of Psychiatry (OpenAlex W7220446021) examined the real-world efficacy of intravenous (IV) ketamine in six patients aged 24-36 with severe, treatment-resistant depression (TRD) and acute suicidal ideation or attempts. Of the six patients treated with a standard subanesthetic dose (0.5 mg/kg over 40 minutes), only three showed a positive response during the acute infusion phase as measured by the Modified Scale for Suicidal Ideation (MSSI). This outcome—50% response—stands in contrast to higher response rates reported in controlled research settings, highlighting the heterogeneity of ketamine's effects in complex, high-risk psychiatric populations.

Mechanisms, Patient Profiles, and Clinical Context

Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been studied for its rapid antidepressant and anti-suicidal effects in major depressive disorder (MDD), particularly in patients unresponsive to standard treatments. The mechanism is believed to involve modulation of glutamatergic neurotransmission and downstream effects on synaptic plasticity, though the precise pathways remain under investigation. This case series included five patients with documented TRD and one with severe MDD and poor treatment adherence, all experiencing acute suicidality—a population at exceptionally high risk and often excluded from large randomized controlled trials (RCTs).

Each patient received ketamine infusions in a high-dependency unit (HDU) under anesthetist supervision, reflecting a cautious approach to safety. The variable response—half benefitting, half not—mirrors the clinical reality that even promising interventions like ketamine are not universally effective, especially in real-world settings where comorbidities, medication adherence, and psychosocial factors complicate outcomes.

Policy and Research Implications: Toward Personalized Psychiatry

This case series underscores the necessity for personalized treatment protocols and careful patient selection when considering ketamine for TRD with suicidality. While previous meta-analyses and RCTs have reported response rates as high as 70% for acute reductions in suicidal ideation, the real-world data from Bangladesh suggest that such efficacy may not generalize to all clinical settings or populations. The findings reinforce the importance of pragmatic trials and observational studies that capture the diversity and complexity of psychiatric patients outside of tightly controlled research environments.

For policymakers and clinical guideline developers, these results argue against a one-size-fits-all approach to ketamine therapy. Instead, they highlight the need for clear criteria regarding patient selection, monitoring protocols, and integration with broader mental health support services. Notably, the study's use of the MSSI for psychometric assessment provides a replicable framework for future studies in similar contexts, especially in resource-limited settings.

Risks, Limitations, and Unanswered Questions

The safety profile of IV ketamine remains a critical concern, particularly in high-risk populations. In this series, infusions were delayed or adjusted in response to side effects, and all procedures occurred in an HDU under anesthetist supervision. However, the small sample size and lack of a control group limit the generalizability of the findings. Moreover, the absence of long-term follow-up data leaves questions about the durability of response and risk of relapse or adverse outcomes.

One underappreciated risk is the potential for ketamine non-responders to experience demoralization or disengagement from care after an unsuccessful trial, especially when expectations are high. This phenomenon, rarely discussed in larger trials, may have significant implications for suicide prevention strategies and underscores the ethical imperative for transparent patient counseling.

Looking Forward: Next Steps for Research and Practice

The heterogeneity observed in this real-world case series points to several priorities for future research: identifying biomarkers or clinical predictors of ketamine response, developing adaptive dosing protocols, and integrating ketamine therapy within comprehensive, multidisciplinary care models. For jurisdictions considering broader access or regulatory approval, these data serve as a cautionary reminder that efficacy in controlled trials may not translate seamlessly to diverse clinical populations.

Ultimately, the findings from Bangladesh contribute to a growing body of evidence emphasizing the need for individualized, context-sensitive approaches to psychedelic and rapid-acting antidepressant therapies. As the field advances, robust post-marketing surveillance and pragmatic studies will be essential to ensure both safety and equity in access to emerging treatments.

How we research: This analysis was prepared by Dr. Alex Nguyen, MD, MPH, clinical psychiatrist and Psychedelic Research Journal contributing editor. Reviewed by Dr. Nguyen on 2026-10-08. Primary source: Bangladesh Journal of Psychiatry case series (2024).