Cetamina na depressão resistente ao tratamento: evidências, limitações e perspectivas clínicas
Revista Sociedade Científica June 13, 2026 Henrique Cardoso de Freitas, Andra Cristina Catelan-Mainardes
About 30% of patients with major depressive disorder do not respond to any antidepressant, characterizing treatment-resistant depression (TRD). This narrative review critically examines evidence on ketamine and esketamine for TRD, including efficacy, mechanisms, safety, and access barriers. Both intravenous ketamine and intranasal esketamine produce rapid antidepressant responses within hours, possibly through glutamatergic modulation and neuroplasticity. In refractory populations, response rates range from 50% to 70%. However, limitations persist: methodological heterogeneity, short follow-up, dissociative effects, abuse potential, high cost, and restricted access, especially in Brazil. Ketamine represents a promising therapeutic alternative for TRD, but broader adoption depends on protocol standardization, long-term safety evaluation, and expanded access.