Anti-Suicidal Effects of Lithium, Ketamine, and Clozapine—A 10-Year Systematic Review

Background/Objectives: Suicide is a complex issue resulting in approximately 700,000 deaths annually. Individuals with mood disorders or schizophrenia are at an increased risk. Pharmacological interventions, such as lithium, clozapine, and ketamine, show promise in reducing suicidality. Methods: A systematic search was conducted across Google Scholar, Scopus, and PubMed to identify studies evaluating the effects of lithium, clozapine, and ketamine on suicidality. Peer-reviewed articles published between 2014 and 2024 that focused on adult populations were included. After screening 1297 records, 49 studies met the eligibility criteria: 14 on lithium, 23 on ketamine, and 12 on clozapine. Results: Multiple studies highlight lithium’s significant anti-suicidal effects in patients with bipolar disorder, showing superior suicide risk reduction compared to valproate and other mood stabilizers. Ketamine has been shown to rapidly reduce suicidal ideation, with effects observable within hours and lasting up to a week. While most studies support its short-term efficacy, findings regarding its long-term benefits and the impact of repeated dosing remain inconsistent. Clozapine has consistently demonstrated a reduction in suicide risk for individuals with schizophrenia. Large-scale cohort studies report a significant decrease in suicide attempts and mortality when compared to other antipsychotics. Conclusions: Lithium, ketamine, and clozapine were proven to be effective in reducing suicidality. However, limited data, adherence challenges, and methodological differences across studies highlight the need for more robust, large-scale experimental research. Effective suicide prevention is an extremely complex topic and also requires consideration of healthcare and social system factors.