Overview

• Investigators reviewed records from 153 adults with treatment-resistant depression treated at McLean Hospital, comparing IV ketamine (n=111) with intranasal esketamine (n=42).
• Across an eight‑treatment, twice‑weekly induction phase, depression scores fell 49.22% with IV ketamine versus 39.55% with esketamine.
• Clinically meaningful improvement appeared after the first IV infusion, whereas esketamine’s significant gains were evident after the second session.
• Esketamine nasal spray is FDA‑approved for depression, while IV ketamine is used off label, influencing insurance coverage and access to care.
• Authors cautioned about misuse risks and variability in provider practices and advised selecting therapy based on clinical context and logistical considerations.