Antisuicidal effect of ketamine as related to primary diagnosisKrzysztof Sadko¹, Olga Genge¹, Katarzyna Jakuszkowiak¹¹Department of Psychiatry, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, PolandTo the Editors,We read with interest the paper “Ketamine for suicidality: An umbrella review” on antisuicidal effect of ketamine [1] . We find this text important and of clinical relevance for the understanding of the effectiveness of this therapeutic intervention.We fully agree with the opinion that ketamine is an effective and safe drug in treatment prevention of thoughts and suicidal tendencies and we understand that side effects as rise in pulse rate and blood pressure, dissociation, confusion, blurred vision, nausea and vertigo occur are mild and temporary [1] .We believe the discussion of the paper may aims to address any confusion that may still exist among the public and even among prescribers, about the relative harm and benefits related to medications and suicide prevention/risk.Ketamine causes a quick onset and a short-term improvement in depression and suicidal symptoms in treatment-resistant depression, it also reduces chronic pain after short intravenous infusions [2] . In 2020, esketamine also received FDA approval for the treatment of depressive symptoms in adults with MDD with suicidal ideation or behavior.The main problem is dissociation as an adverse event of ketamine treatment. Additionally, there is insufficient data collected on this phenomenon in depressed patients treated with ketamine. The conducted research also does not correlate dissociation with treatment results[3] . Although the pathophysiology of the mood disorder is pleomorphic, some diseases may contribute to the development of dissociation disorders [4,5] .We believe that even a single infusion of ketamine is effective and well-tolerated, and that dissociative symptoms resolve within 2 hours of ketamine administration. Single doses of ketamine may be administered to TRD patients with or without suicidal thoughts, even if the effect may be only temporary, as it will significantly improve patients’ quality of life by reducing symptoms of depression [6] .All the studies cited here suggest that the risk of side effects after administration of ketamine may not be related to the drug itself and its enantiomer, but rather is due to the underlying psychiatric diagnosis and the course of the underlying disease. We believe that this remark could contribute to discussion and research design in future research in this field. Moreover, it appears to be of particular importance for patient safety in a clinical setting.Yours faithfully,Krzysztof Sadko
