Ketamine’s efficacy in alleviating acute suicidal thoughts: a comprehensive systematic review and meta-analysis

Suicidal ideation in patients with major depressive disorder (MDD) presents a critical challenge in mental health, with conventional antidepressants often having delayed onset. This systematic review and meta-analysis investigates the efficacy of ketamine in rapidly reducing acute suicidal ideation in this patient group. A comprehensive literature search up to June 2023 across PubMed (Medline), Scopus, Web of Science, and Embase yielded 12 studies, including 7 randomized controlled trials (RCTs). The evaluation of the impact of ketamine on Montgomery-Åsberg Depression Rating Scale-Suicidal Ideation (MADRS-SI) scores was conducted using the standardized mean difference (SMD) through the Cohen’s d method for analysis. The assessment of risk of bias was executed utilizing the Cochrane Risk of Bias Tool (RoB2). Subgroup assessments considered study period, geographic location, and follow-up duration. Ketamine administration showed a significant reduction in MADRS SI scores (mean difference, -1.16; 95% CI, -1.89, -0.23). Subgroup analysis revealed varying efficacy based on the study period, geographical location, and follow-up length. Intravenous ketamine demonstrated the most substantial reduction in suicidal thoughts. High heterogeneity among studies was observed. Ketamine offers a rapid and significant reduction in acute suicidal ideation in patients with MDD. It holds promise as an intervention during high-risk periods where conventional treatments are limited by slower onset. However, variability in study results and concerns over long-term safety necessitate further research to optimize treatment protocols and understand the implications of different administration routes. These findings have important implications for developing clinical guidelines in managing acute suicidal ideation in MDD.