Ketamine or Esketamine in Special Populations of Patients With Treatment-Resistant Depression
Medical Science Monitor February 18, 2026 Łukasz Grabarczyk, Sophia Rebekka Wolfermann, Hubert Oniszczuk et al.
Conventional antidepressants work in only about half of patients with treatment-resistant depression (TRD). Ketamine, a fast-acting NMDA receptor antagonist, offers an alternative. This non-systematic review of preclinical and clinical evidence found that both ketamine and esketamine show efficacy across several TRD subpopulations, including geriatric, psychiatric, neurologic, oncologic, pediatric, and obstetric patients. Key challenges include psychotomimetic effects, abuse potential, and cardiovascular side effects. Preliminary data on arketamine suggest possible longer-lasting benefits with fewer adverse effects. However, many findings come from very small samples, highlighting the need for larger trials to establish definitive safety and efficacy.