Correspondence. Recently, intranasal esketamine spray (Spravato®) was approved by the Food and Drug Administration in the United States of America for its use in treatment‐resistant depression (TRD), after clinical trials demonstrating its antidepressant efficacy and positive effects on suicidal ideation1. The antidepressant mechanisms of action of ketamine‐related molecules, ethical implications, and long‐term safety issues should be addressed.. To read the full article, log in using your NHS Athens details. To access full-text: click “Log in/Register” (top right hand side). Click ‘Institutional Login’ then select 'OpenAthens Federation', then ‘NHS England’. Enter your Athens details to view the article.