The Induction Series: 6 Infusions in 2-3 Weeks

The classic IV induction

• Dose: 0.5 mg/kg over 40 minutes, IV.
• Frequency: 2-3x per week.
• Total: Six infusions over ~2-3 weeks.
• Decision point: Reassess at session 4-6. If no response, most clinicians stop or pivot.

How modalities differ

• IM ketamine: Usually 6-8 sessions on a similar 2-3x weekly cadence; dosing 0.5-1.0 mg/kg.
• Spravato (esketamine): FDA induction is 8 sessions over 4 weeks (twice weekly).
• Sublingual/oral: Often longer induction windows (8-12 sessions, weekly to biweekly) due to lower bioavailability and gentler profile.
• KAP infusion: Lower-frequency model (e.g., 3-6 sessions over 6-12 weeks) interleaved with therapy.

What outcomes typically look like

In trials of TRD, ~50-70% of patients show clinically meaningful response by the end of induction, with ~30% reaching remission. Non-response by session 4-6 is the strongest predictor of non-response overall — continuing further rarely converts non-responders.

After induction

Responders move to maintenance. The shape of maintenance — fixed boosters, taper to none, or symptom-triggered — depends heavily on which condition was treated and how you responded.