Comparative Effects of Repeated Ketamine Infusion Versus Intranasal Esketamine in Patients With Treatment-Resistant Depression

Both intravenous (IV) racemic ketamine and intranasal (IN) esketamine have emerged as rapid-acting antidepressants for treatment-resistant depression (TRD) and are increasingly used in clinical settings. Relatively few studies, however, have compared these interventions in larger, naturalistic cohorts. This study was conducted to assess the comparative efficacy and rapidity of response observed with repeated IV ketamine versus IN esketamine in a psychiatric neurotherapeutics specialty service. Through retrospective chart review, we conducted what is, to the best of our knowledge, among the larger such comparisons to date. scores between the IV ketamine and IN esketamine treatment groups. scores reached significance after the second treatment. In this naturalistic sample of patients with similarly severe TRD treated in a ketamine subspecialty service over a 4-5-week induction period, treatment with IV racemic ketamine was associated with a more rapid response and greater overall efficacy than treatment with IN esketamine.