Efficacy of Oral Ketamine in Patients with Depression and Suicidality: A Retrospective Study.

Background: Depression is a significant global health issue, often accompanied by suicidality, which requires urgent and effective interventions. Oral ketamine is emerging as a potential rapid-acting treatment, but data on its efficacy and tolerability remain limited, particularly in the Indian context. Thus, this retrospective study was conducted to assess the response to oral ketamine in patients with depression and suicidality. Methods: A retrospective cross-sectional study was conducted on 41 patients diagnosed with major depressive disorder (MDD), bipolar depression (bipolar affective disorder [BPAD] depression), or who had suicidal ideation, all of whom were administered oral ketamine therapy at a tertiary care psychiatric institute in India. Depression severity and suicidal ideation were assessed using the Hamilton Depression Rating Scale (HAMD) and the Modified Scale for Suicidal Ideation (MSSI), respectively, at baseline and after the third ketamine session. Sociodemographic and clinical variables were analyzed to explore their association with treatment outcomes. Results: The mean reduction in HAMD and MSSI scores post-third ketamine session was 8.19 (p < .001) and 4.95 (p < .001), respectively, indicating significant improvements in both depressive symptoms and suicidal ideation. Common side effects included dizziness, nausea, and hypertension, and the least common was diarrhea. Conclusions: Oral ketamine appears to be an effective and well-tolerated option for rapidly reducing depressive symptoms and suicidal ideation in patients with MDD and BPAD depression. It can be used in outpatient settings to provide immediate benefit to patients. Future studies with robust, prospective designs are needed to determine optimal dosing, evaluate long-term safety, and establish sustained efficacy.