A genome-wide association study in 527 people of European ancestry with major depressive disorder identified a significant genetic locus in the IRAK3 gene and a significant gene-level association in NME7 linked to the antidepressant efficacy of esketamine nasal spray, measured as percentage change in symptom severity. Polygenic risk score analysis showed the strongest association with esketamine efficacy came from genetic loading for depressive symptoms, though this did not reach study-wide significance. Suggestive signals were enriched in pathways related to neuronal and synaptic function, immune signaling, and glucocorticoid receptor/stress response.
In patients with treatment-resistant depression, adding esketamine nasal spray to a newly initiated oral antidepressant did not harm cognitive function over the short or long term. Across three short-term double-blind studies (747 patients aged 18–64 years) and one long-term maintenance study (137 patients aged 65 or older), cognitive performance on tests of psychomotor function, attention, and memory either remained stable or slightly improved from baseline to the end of treatment. At the start, patients showed mild-to-moderate cognitive impairment. The correlation between depression severity and cognitive performance was weak. The analysis found no evidence that esketamine worsens cognition in treatment-resistant depression.