Key Takeaways
Extended Takeaways
- Baseline depression severity was comparable, but by the end of induction QIDS-SR16 scores fell from 19.23 ± 0.23 to 9.65 ± 0.48 with IV ketamine and from 19.52 ± 0.39 to 11.80 ± 0.65 with IN esketamine, supporting a larger absolute symptom reduction with the IV protocol in this clinic population.
- Separation between treatments emerged early: after the second treatment the groups began to differ significantly, and pretreatment QIDS-SR16 scores were significantly lower in the IV ketamine group from the third through the eighth treatment (all P values < .05).
- Patients who completed induction received the same number of sessions—8 treatments twice weekly over 4–5 weeks—so the observed difference reflects comparative performance within matched induction schedules rather than a longer course for one intervention.
- Terminal dropout was similar despite different routes and regulatory status, with 21% in the IV ketamine group and 17% in the IN esketamine group discontinuing before induction completion (P = .654), suggesting tolerability and practical retention were broadly comparable in routine outpatient care.
- Average end-of-induction doses were 0.67 mg/kg for IV ketamine and 82.67 mg for IN esketamine; clinicians should note that the IV protocol allowed conservative escalation up to 1.0 mg/kg, which may limit direct route-to-route equivalence.
- Concomitant antipsychotic augmentation differed between groups, with 26.2% in the IV ketamine group and 51.4% in the IN esketamine group (P < .05). Because this imbalance may reflect baseline severity differences, comparative response should be interpreted with attention to background treatment burden.
