In adults with treatment-resistant depression who had not responded to at least two prior oral antidepressants, esketamine nasal spray taken alone (without an oral antidepressant) reduced depressive symptoms more than a placebo. Over four weeks, both a 56 mg and an 84 mg dose of esketamine produced significantly greater improvements on the Montgomery-Åsberg Depression Rating Scale than placebo, with effects apparent as early as 24 hours after the first dose. Common side effects included nausea, dissociation, dizziness, and headache. The findings suggest that esketamine monotherapy could offer a new treatment option for patients who cannot tolerate or do not respond to oral antidepressants.
Adding cognitive behavioral therapy to esketamine treatment reduces suicidal ideation more than esketamine alone in people with major depression and suicidal thoughts. In a randomized trial of 93 patients, 72% completed the study, meeting feasibility goals. Those who received 16 weeks of CBT plus esketamine showed greater improvement on three measures of suicidal ideation than those receiving esketamine with usual care: a mean difference of -1.91 on the Beck Scale for Suicidal Ideation, -0.33 on the Clinician Global Improvement Scale for Suicide Severity, and -3.77 on the depression rating scale. No difference was found on the Columbia-Suicide Severity Rating Scale or in suicide-related events.