Conventional antidepressant drugs are effective in only approximately 50% of patients with treatment-resistant depression (TRD). Ketamine, a non-competitive N-methyl-D-aspartate receptor antagonist, offers a promising alternative with an exceptionally rapid antidepressant effect. Although its efficacy in the general TRD population is well established, its use in specific patient subpopulations warrants further investigation. We conducted a comprehensive, non-systematic review of preclinical and ...